(1) greater than the mass of the carbon plus the
mass of the oxygen
(2) equal to the mass of the carbon plus the
when carbon and oxygen combine chemically,
the mass of the product is
(1) greater than the mass of the carbon plus the
mass of the oxygen
(2) equal to the mass of the carbon plus the
mass of the oxygen
(3) equal to the mass of the carbon
(4) less than the mass of the carbon

When carbon and oxygen combine chemically, the mass of the product is (2) equal to the mass of the carbon plus the mass of the oxygen.

Explanation:

The is because of the law of conservation of mass, mass cannot be created or destroyed during a chemical reaction. Therefore the mass of the reactants must be equal to the mass of the products.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).