Balancing Chemical Equations

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

What is the little number after an element in a chemical equation called?
Example: H₂

Is the following equation balanced?
Al + O₂ --> 2Al₂O₃

What is the number before a chemical formula called?
Ex: 2H₂ + O₂ --> 2H₂O

How many aluminum atoms are in Al₂(SO₄)₃?

Is the following reaction balanced?
NaHCO₃ --> Na₂CO₃ + H₂O + CO₂

Balance this equation: _Zn + _O2 --> _ZnO

Is the following equation balanced?
Al + O₂ ---> 2Al₂O₃

In the equation, 2Mg + O₂ ---> 2MgO, which are the reactants?