Question

if 14 atoms of carbon react with 28 atoms of oxygen to form carbon dioxide, how many atoms are contained in the carbon dioxide that is produced?
a) 42
b) 28
c) 21
d) 14

Explanation:

Step1: Recall the law of conservation of mass

According to the law of conservation of mass, the total number of atoms before a chemical reaction is equal to the total number of atoms after the reaction.

Step2: Calculate the total number of atoms

The number of carbon atoms is 14 and the number of oxygen atoms is 28. The total number of atoms before the reaction is $14 + 28=42$. Since the number of atoms is conserved in the formation of carbon - dioxide, the number of atoms in the produced carbon - dioxide is also 42.

Answer:

A. 42