In the activity, you will balance two equations at each level: easy, medium, and hard. The equations to balance are listed below. Solve these equations and write their answers in the space provided.

Easy
1. K + Br2 → KBr

2. Sb + O2 → Sb4O6

Medium
1. Na + H2O → NaOH + H2

2. KNO3 → KNO2 + O2

Hard
1. NH3 + O2 → NO + H2O

2. C2H5OH + O2 → CO2 + H2O

Easy

1. 2K + Br2 → 2KBr

2. 4Sb + 3O2 → Sb4O6

Medium

1. 2Na + 2H2O → 2NaOH + H2

2. 2KNO3 → 2KNO2 + O2

Hard

1. 4NH3 + 5O2 → 4NO + 6H2O

2. C2H5OH + 3O2 → 2CO2 + 3H2O

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.