Which statement best explains why hydrogen’s atomic number is equal to its mass?(1 point)

Question

Responses

Hydrogen only has one electron
Hydrogen only has one electron

Hydrogen is in the first row and the first column of the periodic table.
Hydrogen is in the first row and the first column of the periodic table.

Hydrogen does not have any neutrons.
Hydrogen does not have any neutrons.

Hydrogen is stable, with two electrons in its outer shell.

Answer 1

The statement that best explains why hydrogen’s atomic number is equal to its mass is:

Hydrogen does not have any neutrons.

This is because hydrogen has one proton (which determines its atomic number, 1) and typically one electron. The most common isotope of hydrogen (protium) has no neutrons, so its atomic mass is essentially 1. The atomic number refers to the number of protons, and since hydrogen has no neutrons, its atomic number and mass number are the same for the most common isotope.