1) A substance with specific properties that cannot be broken down or converted into another substance is called a(n):
2) If you examined the human body, which of the following combinations of elements would be most common?
A) C, O, P, S
B) C, Na, O, N
C) Cl, Ca, C, H
D) C, S, Ca, N
E) O, N, H, C
3) The atomic number of an atom is defined as the:
A) number of electrons in the outermost energy level.
B) total number of energy shells.
C) arrangement of neutrons in the atomic nucleus.
D) number of protons in the atomic nucleus.
E) total number of electrons and neutrons.
4) Phosphorus has an atomic number of 15, so what is the distribution of its electrons?
A) The first energy level has eight and the second has seven.
B) The first energy level has two, the second has eight, and the third has five.
C) The first energy level has two and the second has 13.
5) Which four elements make up approximately 96% of living matter?
A) carbon, hydrogen, nitrogen, oxygen
B) carbon, sulfur, phosphorus, hydrogen
C) carbon, sodium, chlorine, magnesium
D) carbon, oxygen, sulfur, calcium
E) oxygen, hydrogen, calcium, sodium
6) Imagine that you have been hired as a chemist and your first task is to examine a newly discovered atom. The paperwork you are given states that its atomic number is 110. What does this mean?
A) The atom contains 110 protons.
B) The atom contains 55 electrons.
C) The atom contains 55 protons and 55 neutrons.
D) The atom is an isotope.
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