Balancing Equations

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

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

• Reactants
• Products 
• Yields 
• Chemical Equation 

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

• Reactants
• Products 
• Yields 
• Chemical Equation 

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

• Coefficient 
• Subscript
• Atom
• Equation

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

• Coefficient
• Subscript
• Atom
• Equation

The red numbers in the image below represent ________

• subscripts
• coefficients
• I don't know, and don't want to try
• None of the answers are correct

The blue numbers in the image below represent ________

• I don't know, and don't want to try
• coefficients
• subscripts
• none of the answers are correct

The substances at the beginning of a chemical equation are called the ____

• product
• yield
• chemical symbol
• reactants

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

• Mg and O
• MgO
• Mg and MgO
• O and MgO

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2
• 6
• 1
• 4