Balancing Equations/Law of Conservation of Mass

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

Is this equation balanced?

• yes
• no
• Not enough information

Is this equation balanced?

• yes
• no
• Not enough information

What is the Law of Conservation of mass?

• Mass is always created in a chemical reaction

• physical change

• New chemicals formed from a chemical reaction have a larger overall mass than the original reactants

• Mass is never created or destroyed

Number written below & to the right of a chemical symbol

• subscript
• reactant
• product
• coefficient

Substances that form as the result of a chemical reaction

• products
• reactants
• coefficients
• subscripts

Substances present at the start of a chemical reaction

• subscripts
• coefficients
• reactants
• products

Is this chemical equation balanced?
2Na + Cl₂ ----> 2NaCl

• Yes
• No

The total amount of matter (atoms) before and after a chemical reaction remains the same.

• True
• False

Which are the reactants in the following reaction?

2Mg + O₂ ---> 2MgO

• Mg and O2

• MgO

• Mg and MgO

• O2 and MgO