Chapter 2

Question 1

atomic number

Answer 1

the number of protons in an elements nucleus

Question 2

mass number

Answer 2

the sum of protons plus neutrons in the nucleus

Question 3

atomic mass

Answer 3

the atom’s total mass, can be approximated by the mass number

Question 4

isotopes

Answer 4

two atoms of an element that differ in number of neutrons (different mass #)

Question 5

valence electrons

Answer 5

those in the outermost shell

Question 6

the chemical behavior of an atom is mostly determined by:

Answer 6

valence electrons

Question 7

elements with a full valence shell are:

Answer 7

chemically inert

Question 8

covalent bond

Answer 8

the sharing of a pair of valence electrons by two atoms

Question 9

nonpolar covalent bond

Answer 9

the atoms share the electron equally

Question 10

polar covalent bond

Answer 10

one atom is more electronegative and the atoms do not share the electron equally

Question 11

unequal sharing of electrons causes:

Answer 11

a partial positive or negative charge for each atom or molecule