Find study materials for any course. Check these out:
Browse by school
Make your own
To login with Google, please enable popups
To login with Google, please enable popups
Don’t have an account?
To signup with Google, please enable popups
To signup with Google, please enable popups
Sign up withor
4) A localized group of organisms that belong to the same species is called a
5) Which of the following is a false statement regarding DNA?
A) Each chromosome has one very long DNA molecule with hundreds of thousands of genes.
B) Every cell is enclosed by a membrane.
C) Every cell uses DNA as its genetic information.
D) All forms of life are composed of cells that have a membrane-enclosed nucleus.
E) DNA is the unit of inheritance that is transmitted from parent to offspring.
In terms of the hierarchical organization of life, a bacterium is at the __________ level of organization, whereas a human is at the __________ level of organization.
A) single-celled organism; multicellular organism
B) single organelle; organism
C) organelle; organ system
D) single tissue; multicellular organism
E) tissue; organism
Which of these is a correct representation of the hierarchy of biological organization from least to most complex?
A) organelle of a stomach cell, digestive system, large intestine, small intestine, intestinal tissue, organism
B) organelle of an intestinal cell, digestive system, small intestine, large intestine, intestinal tissue, organism
C) molecule, intestinal cell organelle, intestinal cell, intestinal tissue, digestive system, organism
D) molecule, small intestine, large intestine, intestinal tissue, digestive system, organism
E) molecule, digestive system, digestive cell organelle, small intestine, large intestine, intestinal cell, organism
Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into
A) the energy of motion.
B) carbon dioxide and water.
C) the potential energy of chemical bonds.
E) kinetic energy.
The main source of energy for producers in an ecosystem is
A) light energy.
B) kinetic energy.
C) thermal energy.
D) chemical energy.
The dynamics of any ecosystem include the following major processes:
A) the flow of energy from sunlight to producers
B) the flow of energy from sunlight to producers and then to consumers
C) the recycling of chemical nutrients
D) the flow of energy to producers and the recycling of nutrients
E) the flow of energy from sunlight to producers and then to consumers, and the recycling of chemical nutrients.
For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________.
A) sunlight; heat
B) heat; light
C) plants; animals
D) plants; heat
E) producers; consumers
12) The illustration above represents
A) a computer simulation of the structure of a eukaryotic cell.
B) a map of a network of protein interactions within a eukaryotic cell.
C) an inventory of all the genes in a fruit fly.
D) an X-ray diffraction image of the nucleus and cytoplasm of a eukaryotic cell.
E) a computer generated map of the interaction of genes and cytoplasm in a prokaryotic cell.
The lowest level of biological organization that can perform all the activities required for life is the
A) organelle–for example, a chloroplast.
B) cell–for example, a skin cell.
C) tissue–for example, nervous tissue.
D) organ system–for example, the reproductive system.
E) organism–for example, an amoeba, dog, human, or maple tree.
Which of the following is a false statement regarding deoxyribonucleic acid (DNA)?
A) Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix.
B) Genes are composed of deoxyribonucleic acid.
C) DNA is composed of chemical building blocks called nucleotides.
D) DNA is a code for the sequence of amino acids in a protein.
E) DNA is an enzyme that puts together amino acids to make a protein.
Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?
Which of the following statements concerning prokaryotic and eukaryotic cells is not correct?
A) Prokaryotic cells lack a membrane-bound nucleus.
B) Prokaryotic cells contain small membrane-enclosed organelles.
C) Eukaryotic cells contain a membrane-bound nucleus.
D) DNA, or deoxyribonucleic acid, is present in both prokaryotic cells and eukaryotic cells.
E) DNA or deoxyribonucleic acid is present in the nucleus of eukaryotic cells.
Which of the following is reflective of the phrase "the whole is greater than the sum of its parts"?
A) high-throughput technology
B) emergent properties
C) natural selection
E) feedback regulations
In order to understand the chemical basis of inheritance, one must understand the molecular structure of DNA. This is an example of the application of __________ to the study of biology.
B) emergent properties
D) the cell theory
E) feedback regulation
A type of protein critical to all cells is organic catalysts called
A) feedback activators.
B) feedback inhibitors.
Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of
A) a bioinformatic system.
B) positive feedback.
C) negative feedback.
D) feedback inhibition.
E) enzymatic catalysis.
When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of
A) catalytic feedback.
B) positive feedback.
C) negative feedback.
D) bioinformatic regulation.
E) protein-protein interactions.
Life is diverse. How many species are estimated to be presently on the earth?
Which branch of biology is concerned with the naming and classifying of organisms?
B) schematic biology
Prokaryotic and eukaryotic cells generally have which of the following features in common?
A) a membrane-bounded nucleus
B) a cell wall made of cellulose
D) flagella or cilia that contain microtubules
E) linear chromosomes made of DNA and protein
Prokaryotes are classified as belonging to two different domains. What are the domains?
A) Bacteria and Eukarya
B) Archaea and Monera
C) Eukarya and Monera
D) Bacteria and Protista
E) Bacteria and Archaea
Species that are in the same __________ are more closely related than species that are only in the same __________.
A) phylum; class
B) family; order
C) class; order
D) family; genus
E) kingdom; phylum
Two species that belong to the same genus must also belong to the same
E) all of the above
Which of these is reflective of the hierarchical organization of life from most to least inclusive?
A) kingdom, order, family, phylum, class, genus, species
B) phylum, class, order, kingdom, family, genus, species
C) kingdom, phylum, class, order, family, genus, species
D) genus, species, kingdom, phylum, class, order, family
E) class, order, kingdom, phylum, family, genus, species
A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification?
A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism?
A) domain Bacteria, kingdom Prokaryota
B) domain Archaea, kingdom Bacteria
C) domain Eukarya, kingdom Plantae
D) domain Eukarya, kingdom Protista
E) domain Eukarya, kingdom Fungi
Which of these provides evidence of the common ancestry of all life?
A) the ubiquitous use of catalysts by living systems
B) the universality of the genetic code
C) the structure of the nucleus
D) the structure of cilia
E) the structure of chloroplasts
Which of the following is (are) true of natural selection?
A) requires genetic variation
B) results in descent with modification
C) involves differential reproductive success
D) B and C only
E) A, B, and C
Charles Darwin proposed a mechanism for descent with modification which stated that organisms of a particular species are adapted to their environment when they possess
A) non-inheritable traits that enhance their survival in the local environment.
B) non-inheritable traits that enhance their reproductive success in the local environment.
C) non-inheritable traits that enhance their survival and reproductive success in the local environment.
D) inheritable traits that enhance their survival and reproductive success in the local environment.
E) inheritable traits that decrease their survival and reproductive success in the local environment.
All of the following statements are part of Charles Darwin's concept of natural selection except
A) Slight inheritable variations within a population may make an individual significantly more or less likely to survive in its environment, and thus to reproduce.
B) Every organism has the potential to produce more offspring than the local environment can support.
C) Characteristics of organisms are inherited as genes on chromosomes.
D) Better adapted members of a species will survive and reproduce more successfully.
E) Most individuals in a species do not survive to reproduce.
Which of these individuals is most likely to be successful in an evolutionary sense?
A) a reproductively sterile individual who never falls ill
B) an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce
C) a male who mates with 20 females and fathers 1 offspring
D) an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce
E) a female who mates with 20 males and produces 1 offspring
In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will
A) remain unchanged.
B) gradually decline.
C) rapidly decline.
D) gradually increase.
E) rapidly increase.
Through time, the lineage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by
A) natural philosophy.
C) the hierarchy of the biological organization of life. D) natural selection.
E) feedback inhibition.
Evolution is biology's core theme that ties together all the other themes. This is because evolution explains
A) the unity and diversity of life.
B) how organisms become adapted to their environment through the differential reproductive success of varying individuals.
C) why distantly related organisms sometimes resemble each other.
D) explains why some organisms have traits in common.
E) all of the above
The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as
A) hypothesis-based science.
B) discovery science.
C) experimental science.
D) quantitative science.
E) qualitative science.
What is a hypothesis?
A) the same thing as an unproven theory
B) a tentative explanation that can be tested and is falsifiable
C) a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation
D) a fact based on qualitative data that is testable
E) a fact based on quantitative data that is falsifiable
Which of these is based on a deduction?
A) My car won't start.
B) My car's battery is dead.
C) My car is out of gas.
D) I lost my car key.
E) If I turn the key in the ignition while stepping on the gas pedal, then my car will start.
When applying the process of science, which of these is tested?
A) a question
B) a result
C) an observation
D) a prediction
E) a hypothesis
A controlled experiment is one in which
A) the experiment is repeated many times to ensure that the results are accurate.
B) the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
C) there are at least two groups, one of which does not receive the experimental treatment.
D) there are at least two groups, one differing from the other by two or more variables.
E) there is one group for which the scientist controls all variables.
Why is it important that an experiment include a control group?
A) The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results.
B) The control group provides a reserve of experimental subjects.
C) A control group is required for the development of an "if, then" statement.
D) A control group assures that an experiment will be repeatable.
E) Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor.
The application of scientific knowledge for some specific purpose is known as
B) deductive science.
C) inductive science.
D) anthropologic science.
E) pure science
A common form of regulation in which accumulation of an end product of a process slows that process is called positive feedback. True or false?
Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. True or false?
Recent evidence points to the conclusion that the ancestral finches of the Galapagos originated in the islands of the Caribbean. True or false?
Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. True or false?
In hypothesis-based science, deductive reasoning is used to predict a result that would be found if a particular hypothesis is correct. True or false?
Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method. True or false?
Science requires that hypothesis be testable and falsifiable and that observations be repeatable. True or false?
The goal of systems biology is to construct models to predict the emergent properties of cells. True or false?
All the organisms on your campus make up
A) an ecosystem.
B) a community.
C) a population.
D) an experimental group.
E) a taxonomic domain.
Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal?
A) brain, organ system, nerve cell, nervous tissue
B) organ system, nervous tissue, brain
C) organism, organ system, tissue, cell, organ
D) nervous system, brain, nervous tissue, nerve cell
E) organ system, tissue, molecule, cell
Which of the following is not an observation or inference on which Darwin's theory of natural selection is based?
A) Poorly adapted individuals never produce offspring.
B) There is heritable variation among individuals.
C) Because of overproduction of offspring, there is competition for limited resources.
D) Individuals whose inherited characteristics best fit them to the environment will generally produce more offspring.
E) A population can become adapted to its environment.
Systems biology is mainly an attempt to
A) understand the integration of all levels of biological organization from molecules to the biosphere.
B) simplify complex problems by reducing the system into smaller, less complex units.
C) construct models of the behavior of entire biological systems.
D) build high-throughput machines for the rapid acquisition of biological data.
E) speed up the technological application of scientific knowledge.
Protists and bacteria are grouped into different domains because
A) protists eat bacteria.
B) bacteria are not made of cells.
C) protists have a membrane-bounded nucleus, which bacterial cells lack.
D) bacteria decompose protists.
E) protists are photosynthetic.
Which of the following best demonstrates the unity among all organisms?
A) matching DNA nucleotide sequences
B) descent with modification
C) the structure and function of DNA
D) natural selection
E) emergent properties
Which of the following is an example of qualitative data?
A) The temperature decreased from 20°C to 15°C.
B) The plant's height is 25 centimeters (cm).
C) The fish swam in a zig-zag motion.
D) The six pairs of robins hatched an average of three chicks.
E) The contents of the stomach are mixed every 20 seconds.
Which of the following best describes the logic of hypothesis-based science?
A) If I generate a testable hypothesis, tests and observations will support it.
B) If my prediction is correct, it will lead to a testable hypothesis.
C) If my observations are accurate, they will support my hypothesis.
D) If my hypothesis is correct, I can expect certain test results.
E) If my experiments are set up right, they will lead to a testable hypothesis.
A controlled experiment is one that
A) proceeds slowly enough that a scientist can make careful records of the results.
B) may include experimental groups and control groups tested in parallel.
C) is repeated many times to make sure the results are accurate.
D) keeps all environmental variables constant.
E) is supervised by an experienced scientist.
Which of the following statements best distinguishes hypotheses from theories in science? A) Theories are hypotheses that have been proved.
B) Hypotheses are guesses; theories are correct answers.
C) Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.
D) Hypotheses and theories are essentially the same thing.
E) Theories are proved true in all cases; hypotheses are usually falsified by tests.
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?
A) carbon, sodium, hydrogen, nitrogen
B) carbon, oxygen, phosphorus, hydrogen
C) oxygen, hydrogen, calcium, nitrogen
D) carbon, hydrogen, nitrogen, oxygen
E) carbon, oxygen, nitrogen, calcium
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants?
Which of the following statements is false?
A) Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter.
B) Some trace elements are very abundant on Earth.
C) Virtually all organisms require the same elements in the same quantities.
D) Iron is an example of an element needed by all organisms.
E) Other than some trace elements, animals are mostly made up of the same elements as plants, in similar proportions.
What factors are most important in determining which elements are most common in living matter?
A) the relative abundances of the elements in Earth's crust and atmosphere
B) the emergent properties of the simple compounds made from these elements
C) the reactivity of the elements with water
D) the chemical stability of the elements
E) both the relative abundances of the elements and the emergent properties of the compounds made from these elements
Why is each element unique and different from other elements in chemical properties?
A) Each element has a unique atomic mass.
B) Each element has a unique atomic weight.
C) Each element has a unique number of protons in its nucleus.
D) Each element has a unique number of neutrons in its nucleus.
E) Each element has different radioactive properties.
Knowing just the atomic mass of an element allows inferences about which of the following?
A) the chemical properties of the element
B) the number of protons in the element
C) the number of neutrons in the element
D) the number of protons plus neutrons in the element
E) both the number of protons and the chemical properties of the element
In what way are elements in the same column of the periodic table the same?
A) They have the same number of protons.
B) They have the same number of neutrons.
C) They have the same number of electrons.
D) They have the same number of electrons in their valence shell.
E) They have the same number of electron shells.
Oxygen has an atomic number of 8 and a mass number of 16. Thus, what is the atomic mass of an oxygen atom?
A) exactly 8 grams
B) exactly 8 daltons
C) approximately 16 grams
D) approximately 16 daltons
E) 24 amu (atomic mass units)
The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
A) The nitrogen atom has a mass number of approximately 7 daltons and an atomic mass of 14.
B) The nitrogen atom has a mass number of approximately 14 daltons and an atomic mass of 7.
C) The nitrogen atom has a mass number of 14 and an atomic mass of 7 grams.
D) The nitrogen atom has a mass number of 7 and an atomic number of 14.
E) The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons.
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers of 92, 94, 95, 96, 97, 98, and 100. Therefore, which of the following can be true?
A) Molybdenum atoms can have between 50 and 58 neutrons.
B) The isotopes of molybdenum have different electron configurations.
C) The isotopes of molybdenum can have between 50 and 58 protons.
D) The isotopes of molybdenum have between 50 and 58 neutrons and have different electron configurations.
E) The isotopes of molybdenum have between 50 and 58 protons and have different electron configurations.
Carbon-12 is the most common isotope of carbon, and has an atomic mass of 12 daltons. A mole of carbon in naturally occurring coal, however, weighs slightly more than 12 grams. Why?
A) The atomic mass does not include the mass of electrons.
B) Some carbon atoms in nature have an extra proton.
C) Some carbon atoms in nature have more neutrons.
D) Some carbon atoms in nature have a different valence electron distribution.
E) Some carbon atoms in nature have undergone radioactive decay.
Which of the following best describes the relationship between the atoms described below?
Atom 1 Atom 2
A) They are isomers.
B) They are polymers.
C) They are isotopes.
D) They contain 1 and 3 protons, respectively.
E) They each contain 1 neutron.
The precise weight of a mole of some pure elements like silicon (Si) can vary slightly from the standard atomic mass, or even from sample to sample. Why?
A) The element may undergo radioactive decay.
B) The element may react with itself and gain or lose subatomic particles.
C) The atoms of the element form chemical bonds with each other, and that changes the weight of the element.
D) The element may have multiple stable isotopes, and the isotopic composition may vary from sample to sample.
E) The amount of energy absorbed by the element affects the mass of its electrons, and thus the atomic mass can vary slightly.
One difference between carbon-12 ( ) is that carbon-14 ( ) has
A) two more protons than carbon-12.
B) two more electrons than carbon-12.
C) two more neutrons than carbon-12.
D) two more protons and two more neutrons than carbon-12.
E) two more electrons and two more neutrons than carbon-12.
An atom has 6 electrons in its outer shell. How many unpaired electrons does it have?
E) 2 or 4
The atomic number of nitrogen is 7. Nitrogen-15 is heavier than nitrogen-14 because the atomic nucleus of nitrogen-15 contains how many neutrons?
Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that
A) an electron may move to an electron shell farther away from the nucleus.
B) an electron may move to an electron shell closer to the nucleus.
C) the atom may become a radioactive isotope.
D) the atom would become a positively charged ion, or cation, and become a radioactive isotope.
E) the atom would become a negatively charged ion, or anion.
The atomic number of neon is 10. Therefore, which of the following is most correct about an atom of neon?
A) It has 8 electrons in its outer electron shell.
B) It is inert.
C) It has an atomic mass of 10 daltons.
D) It has 8 electrons in its outer electron shell and it is inert.
E) It has 8 electrons in its outer electron shell, it is inert, and it has an atomic mass of 10 daltons.
From its atomic number of 15, it is possible to predict that the phosphorus atom has
A) 15 neutrons.
B) 15 protons.
C) 15 electrons.
D) 8 electrons in its outermost electron shell.
E) 15 protons and 15 electrons.
Atoms whose outer electron shells contain 8 electrons tend to
A) form ions in aqueous solutions.
B) form hydrogen bonds in aqueous solutions.
C) be stable and chemically nonreactive, or inert.
D) be gaseous at room temperature.
E) be both chemically inert and gaseous at room temperature.
The atomic number of each atom is given to the left of each of the elements below. Which of the atoms has the same valence as carbon ( )?
A) 7N nitrogen
B) 9F flourine
C) 10Ne neon
D) 12Mg magnesium
E) 14Si silicon
Two atoms appear to have the same mass number. These atoms
A) must have the same atomic number.
B) must have the same number of electrons.
C) must have the same chemical properties.
D) must have the same number of protons + neutrons.
E) must have the same atomic number, the same number of protons + neutrons, the same number of electrons, and the same chemical properties.
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?
What is the maximum number of electrons in a single 2 p orbital of an atom?
The organic molecules in living organisms have a measurably lower ratio of carbon-13/carbon-12, two stable isotopes of carbon that comprise approximately 1.1% and 98.9% of atmospheric carbon, respectively. What is a reasonable explanation for this phenomenon?
A) Photosynthesis preferentially uses carbon dioxide molecules with carbon-12, and the lower carbon-13/carbon-12 ratio propagates through the food chain.
B) Carbon dioxide molecules with carbon-13 stay in the upper atmosphere and are less available to terrestrial plants and algae.
C) Carbon-13 has a different valence electron configuration and is therefore less chemically reactive than carbon-12.
D) Oxygen atoms preferentially react with carbon-13, thereby enriching the atmosphere with carbon dioxide molecules containing carbon-13 atoms.
E) Carbon dioxide molecules containing carbon-13 are heavier and sink into the ocean depths, making them less available to living organisms.
Phosphorus-32, a radioactive isotope of phosphorus-31 (atomic number 15), undergoes a form of radioactive decay whereby a neutron turns into a proton and emits radiation in the form of an electron. What is the product of such radioactive decay of phosphorus-32?
B) a positively charged phosphorus-31 ion
C) a negatively charged phosphorus-32 ion
D) sulfur-32 (atomic number 16)
E) the conversion of the phosphorus-32 atom into pure energy
An atom with atomic number 12 would have what type of chemical behavior in bonding with other elements?
A) It would form ions with a +1 charge.
B) It would form ions with a +2 charge.
C) It would form ions with a -1 charge.
D) It would form ions with a -2 charge.
E) It would form two covalent bonds with other atoms.
If a salamander relied on hydrogen bonds to cling to surfaces, what type of surface would cause the most problems for this animal?
A) a surface coated with a thin film of water
B) a surface made with carbon and hydrogen atoms covalently bonded together
C) a surface made with carbon, hydrogen, and oxygen atoms covalently bonded together
D) a surface made with carbon, hydrogen, nitrogen, and oxygen atoms covalently bonded together
E) a surface made with silicon and oxygen atoms covalently bonded together
A covalent chemical bond is one in which
A) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged.
B) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms.
C) outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.
D) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom.
E) an electron occupies a hybrid orbital located between the nuclei of two atoms.
What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following statements is correct about the atoms in ammonia (NH3)?
A) Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.
B) The nitrogen atom has a strong positive charge; each hydrogen atom has a strong positive charge.
C) Each hydrogen atom has a slight negative charge; the nitrogen atom has a strong positive charge.
D) The nitrogen atom has a slight positive charge; each hydrogen atom has a slight negative charge.
E) There are covalent bonds between the hydrogen atoms and polar bonds between each hydrogen atom and the nitrogen atom.
When two atoms are equally electronegative, they will interact to form
A) hydrogen bonds.
B) van der Waals interactions.
C) polar covalent bonds.
D) nonpolar covalent bonds.
E) ionic bonds.
What results from an unequal sharing of electrons between atoms?
A) a nonpolar covalent bond
B) a polar covalent bond
C) an ionic bond
D) a hydrogen bond
E) a hydrophobic interaction
A covalent bond is likely to be polar when
A) one of the atoms sharing electrons is much more electronegative than the other atom.
B) the two atoms sharing electrons are equally electronegative.
C) oxygen is one of the two atoms sharing electrons.
D) one of the atoms has absorbed more energy than the other atom.
E) the two atoms sharing electrons are different elements.
Which of the following molecules contains the most polar covalent bond?
In comparing covalent bonds and ionic bonds, which of the following would you expect?
A) An atom can form covalent bonds with multiple partner atoms, but only a single ionic bond with a single partner atom.
B) Covalent bonds and ionic bonds occupy opposite ends of a continuous spectrum, from nearly equal to completely unequal sharing of electrons.
C) Both involve electrical attraction between the electrons of one atom and the nucleus of the other atom.
D) Ionic interactions remain when covalent bonds are broken in water. Ionic bonds are much stronger than covalent bonds.
What is the difference between covalent bonds and ionic bonds?
A) Covalent bonds are formed between atoms to form molecules; ionic bonds are formed between atoms to form compounds.
B) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms.
C) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms.
D) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between atoms.
E) Covalent bonds involve the transfer of electrons between atoms; ionic bonds involve the sharing of electrons between atoms.
In ammonium chloride salt (NH4Cl) the anion is a single chloride ion, Cl. What is the cation of NH4Cl?
A) N, with a charge of +1
B) NH, with a charge of +1
C) H3, with a charge of +1
D) NH4, with a charge of +1
E) NH4, with a charge of +4
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?
How many electron pairs are shared between carbon atoms in a molecule that has the formula C2H4?
Which bond or interaction would be difficult to disrupt when compounds are put into water?
A) covalent bond
B) hydrogen bond
C) van der Waals interaction
D) ionic bond
E) either covalent bonds or ionic bonds
Which of the following explains most specifically the attraction of water molecules to one another?
A) nonpolar covalent bond
B) polar covalent bond
C) ionic bond
D) hydrogen bond
E) hydrophobic interaction
Van der Waals interactions result when
A) hybrid orbitals overlap.
B) electrons are not symmetrically distributed in a molecule.
C) molecules held by ionic bonds react with water.
D) two polar covalent bonds react.
E) a hydrogen atom loses an electron.
What bonding or interaction is most likely to occur among a broad array of molecules of various types (polar, nonpolar, hydrophilic, hydrophobic)?
A) covalent bonding
B) polar covalent bonding
C) ionic bonding
D) hydrogen bonding
E) van der Waals interactions
Which of the following is not considered to be a weak molecular interaction?
A) a covalent bond
B) a van der Waals interaction
C) an ionic bond in the presence of water
D) a hydrogen bond
E) both a hydrogen bond and a covalent bond
Which of the following would be regarded as compounds?
A) H2O, O2, and CH4
B) H2O and O2
C) O2 and CH4
D) CH4 and O2, but not H2O
E) H2O and CH4, but not O2
What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms?
Which of the following is true for this reaction?
3 H2 + N2 ↔ 2 NH3
A) The reaction is nonreversible.
B) Hydrogen and nitrogen are the reactants of the reverse reaction.
C) Hydrogen and nitrogen are the products of the forward reaction.
D) Ammonia is being formed and decomposed.
E) Hydrogen and nitrogen are being decomposed.
Which of the following correctly describes chemical equilibrium?
A) Forward and reverse reactions continue with no effect on the concentrations of the reactants and products.
B) Concentrations of products are higher than the concentrations of the reactants.
C) Forward and reverse reactions have stopped so that the concentration of the reactants equals the concentration of the products.
D) Reactions stop only when all reactants have been converted to products.
E) There are equal concentrations of reactants and products, and the reactions have stopped.
Which of the following correctly describes any reaction that has reached chemical equilibrium?
A) The concentration of the reactants equals the concentration of the products.
B) The rate of the forward reaction is equal to the rate of the reverse reaction.
C) All of the reactants have been converted to the products of the reaction.
D) All of the products have been converted to the reactants of the reaction.
E) Both the forward and the reverse reactions have stopped with no net effect on the concentration of the reactants and the products.
Which of these systems is least likely to be at chemical equilibrium?
A) a test tube of living cells
B) a test tube of organic molecules, kept in the freezer
C) a test tube of dry organic molecules, kept at room temperature
D) a test tube of organic molecules dissolved in water, kept at room temperature
E) a test tube of dead cells in water, kept at room temperature
53) Refer to the figure above (first three rows of the periodic table). If life arose on a planet where carbon is absent, which element might fill the role of carbon?
54) Which drawing in the figure above depicts the electron configuration of an element with chemical properties most similar to Helium (2He)?
Which drawing in the figure above depicts the electron configuration of an atom that can form covalent bonds with two hydrogen atoms?
Which drawing in the figure above depicts the electron configuration of an atom capable of forming three covalent bonds with other atoms?
Which drawing in the figure above is of the electron configuration of a sodium 11Na+ ion?
Which drawing in the figure above depicts the most electronegative atom?
Which drawing in the figure above depicts an atom with a valence of 3?
Which drawing in the figure above depicts an atom with a valence of 2?
61) In the figure above, how many electrons does nitrogen have in its valence shell?
In the figure above, how many unpaired electrons does phosphorus have in its valence shell?
How many neutrons are present in the nucleus of a phosphorus-32 (32P) atom (see the figure above)?
How many electrons does an atom of sulfur have in its valence shell (see the figure above)?
Based on electron configuration, which of these elements in the figure above would exhibit a chemical behavior most like that of oxygen?
66) The illustration above shows a representation of formic acid. A formic acid molecule
A) will form hydrogen bonds with water molecules.
B) has a tetrahedral configuration of hybrid electron orbitals for the carbon atom.
C) consists of largely nonpolar covalent bonds.
D) is held together by hydrogen bonds.E) has a tetrahedral shape and will form hydrogen bonds with water molecules
67) What results from the chemical reaction illustrated above?
A) a cation with a net charge of +1
B) a cation with a net charge of -1
C) an anion with a net charge of +1
D) an anion with a net charge of -1
E) a cation with a net charge of +1 and an anion with a net charge of -1
What is the atomic number of the cation formed in the reaction illustrated above?
What causes the shape of the molecule shown above?
A) the configuration of the 2 p orbitals in the carbon atom
B) the configuration of the 1 s orbital in the carbon atom
C) the configuration of the sp hybrid orbitals of the electrons shared between the carbon and hydrogen atoms
D) the packing of the carbon and hydrogen atoms in a crystal latticeE) hydrogen bonding configurations between the carbon and hydrogen atoms
70) In the methane molecule shown in the figure above, bonds have formed that include both the s orbital valence electrons of the hydrogen atoms and the p orbital valence electrons of the carbon. The electron orbitals in these bonds are said to be
A) double orbitals.
B) tetrahedral orbitals.
C) complex orbitals.
D) hybrid orbitals.
E) polar orbitals.
A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone?
A) a compound with the same number of carbon atoms as the hormone
B) a compound with the same molecular mass (measured in daltons) as the hormone
C) a compound with the same three-dimensional shape as part of the hormone
D) a compound with the same number of orbital electrons as the hormone
E) a compound with the same number of hydrogen and nitrogen atoms as the hormone
In the term trace element, the modifier trace means that
A) the element is required in very small amounts.
B) the element can be used as a label to trace atoms through an organism's metabolism.
C) the element is very rare on Earth.
D) the element enhances health but is not essential for the organism's long-term survival.
E) the element passes rapidly through the organism.
Compared with 31P, the radioactive isotope 32P has
A) a different atomic number.
B) a different charge.
C) one more proton.
D) one more electron.
E) one more neutron.
The reactivity of an atom arises from
A) the average distance of the outermost electron shell from the nucleus.
B) the existence of unpaired electrons in the valence shell.
C) the sum of the potential energies of all the electron shells.
D) the potential energy of the valence shell.
E) the energy difference between the s and p orbitals.
Which statement is true of all atoms that are anions?
A) The atom has more electrons than protons.
B) The atom has more protons than electrons.
C) The atom has fewer protons than does a neutral atom of the same element.
D) The atom has more neutrons than protons.
E) The net charge is 1-.
Which of the following statements correctly describes any chemical reaction that has reached equilibrium?
A) The concentrations of products and reactants are equal.
B) The reaction is now irreversible.
C) Both forward and reverse reactions have halted.
D) The rates of the forward and reverse reactions are equal.
E) No reactants remain.
We can represent atoms by listing the number of protons, neutrons, and electronsfor example,
2p+; 2n0; 2e- for helium. Which of the following represents the 18O isotope of oxygen?
A) 6p+, 8n0, 6e-
B) 8p+, 10n0, 8e-
C) 9p+, 9n0, 9e-
D) 7p+, 2n0, 9e-
E) 10p+, 8n0, 9e-
The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound:
What coefficients must be placed in the following blanks so that all atoms are accounted for in the products?
C6H12O6 → ____ C2H6O + ____ CO2
A) 1; 2
B) 3; 1
C) 1; 3
D) 1; 1
E) 2; 2
Sign up for free and study better.
Get started today!