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

Question

Hydrogen is in the first row and the first column of the periodic table.
• Hydrogen only has one electron
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.

Hydrogen's atomic number is 1, which means it has one proton. The most common isotope of hydrogen (protium) has no neutrons, so its atomic mass is approximately 1 (since the atomic mass is based on the number of protons and neutrons). This correspondence is specific to hydrogen because other elements typically have both protons and neutrons contributing to their atomic mass.