Question

answer each of the following by choosing the best answer choice. 3 points each.

1. a chemical bond occurs when

a. two atoms combine to form a molecule.
b. two elements combine to form a compound.
c. two mixtures combine to form a compound.
d. two substances are heated up together.

1. covalent bonds occur between

a. two metals
b. a metal and nonmetal
c. two nonmetals
d. cations

1. which region on the periodic table would you most

likely find the elements involved in covalent bonds?
a. 1
b. 2
c. 3
d. 4

1. the valence electrons in a covalent bond are

a. shared
b. transferred
c. erased
d. redistributed

1. covalent bonds often have ____ melting points.

a. high
c. low
b. average
d. no

1. solid covalent compounds tend to be

a. hard
c. squishy
b. soft
d. almost liquid like

1. which of the following is true about valence electrons?

a. valence electrons can be found in the nucleus of an atom.
b. valence electrons are the electrons closest to the nucleus of an atom.
c. valence electrons are the outermost electrons of an atom.
d. valence electrons only move in perfect concentric circles around the nucleus of
the atom.

1. how many valence electrons does oxygen contain?

a. 4
c. 8
b. 6
d. 16

Explanation:

1. A chemical bond is formed when two atoms combine to form a molecule.
2. Covalent bonds occur between two nonmetals.
3. Nonmetals are mainly in region 4 of the periodic table.
4. In a covalent bond, valence electrons are shared.
5. Covalent bonds often have low melting points.
6. Solid covalent compounds tend to be soft.
7. Valence electrons are the outermost electrons of an atom.
8. Oxygen has 6 valence electrons.

Answer:

1. a. two atoms combine to form a molecule.
2. c. Two nonmetals
3. d. 4
4. a. Shared
5. c. Low
6. b. Soft
7. c. Valence electrons are the outermost electrons of an atom.
8. b. 6