1. Using the periodic table, what molecules have a stable configuration that satisfies the octet rule for all atoms?

MgBr
MgO
SiO
KCl2

2. Which type of reaction is Mg+2Naf --> MgF2+2Na?

combination (synthesis)
single replacement
double replacement
decomposition
combustion

3. Two carbon atoms (C, group 14) bond with two hydrogen atoms (H, group 1) to form acetylene, C2H2. Which of the following correctly describes the bonds formed by each carbon atom?

Each carbon atom would share one pair of electrons with a hydrogen and one pair of electrons with the other carbon.
Each carbon atom would share one pair of electrons with each hydrogen and two pairs of electrons with the other carbon.
Each carbon atom would share one pair of electrons with one hydrogen and three pairs of electrons with the other carbon.
Each carbon atom would share two pairs of electrons with a hydrogen and two pairs of electrons with the other carbon.

4. Which of the following shows the correctly balanced chemical reaction equation H₂SO₄ reacting with HI?

2H₂SO₄ + 2HI --> 2H₂S + I₂ + 4H₂O
H₂SO₄ + HI --> H₂S + I₂ + H₂O
H₂SO₄ + 8HI --> H₂S + 8I₂ + 4H₂O
H₂SO₄ + 8HI --> H₂S + 4I₂ + 4H₂O

5. Which series of numbers below correctly fill the blanks to balance the equation: _______NaCl + 2SO₂ + _______ H₂O + O₂ --> _______Na₂SO₄ + 4HCl?

2, 1, 2
2, 1, 4
4, 2, 2
2, 2, 2

1. a
2. c
3. d
4. d
5. b