Question

use the equation to answer the question.
$_{1}^{2}h + _{1}^{2}h
ightarrow _{2}^{4}h+\text{energy}$
which statement best describes the mass numbers of the atoms in the reaction?
(1 point)
○ there are two atoms with mass numbers of 1.
○ there are two atoms with mass numbers of 2.
○ there is one atom with a mass number of 2.
○ there is one atom with a mass number of 1.

Explanation:

Step1: Identify mass - numbers in the equation

The reaction is $_{1}^{2}\text{H}+_{1}^{2}\text{H}
ightarrow_{2}^{4}\text{H}+ \text{energy}$. The superscript represents the mass - number.

Step2: Count the atoms with each mass - number

There are two atoms of $_{1}^{2}\text{H}$, which means there are two atoms with a mass number of 2, and one atom of $_{2}^{4}\text{H}$ with a mass number of 4.

Answer:

There are two atoms with mass numbers of 2.