21H+ 21H→ 42H+energy Which statement best describes the mass numbers of the atoms in the reaction? (1 point) Responses There is one atom with a mass number of 2. There is one atom with a mass number of 2. There are two atoms with mass numbers of 1. There are two atoms with mass numbers of 1. There are two atoms with mass numbers of 2. There are two atoms with mass numbers of 2. There is one atom with a mass number of 1.

Answer 1

In the reaction \( ^1H + ^1H \rightarrow ^2H + \text{energy} \), there are two hydrogen atoms (each with a mass number of 1) that combine to form one deuterium atom (with a mass number of 2) along with energy.

To analyze the mass numbers involved:

• The reactants are two atoms of hydrogen, each with a mass number of 1.
• The product is one atom (deuterium) with a mass number of 2.

Thus, the best statement that describes the mass numbers of the atoms in the reaction is:

There are two atoms with mass numbers of 1.