Question

1. according to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ___ the sum of the masses of the individual elements.

a. equal to
b. less than
c. greater than
d. either greater than or less than

Explanation:

Apply the law of conservation of mass

$$ \text{Mass of Reactants} = \text{Mass of Products} $$

Relate reactants to products

$$ \text{Mass of (Sodium + Hydrogen + Oxygen)} = \text{Mass of Compound} $$

Determine the correct relationship

$$ \text{Mass of Compound} = \text{Sum of the masses of the individual elements} $$

Answer:

• a. equal to (Correct answer)
• b. less than
• c. greater than
• d. either greater than or less than