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

Question

• Hydrogen does not have any neutrons.
Hydrogen only has one electron
• Hydrogen is stable, with two electrons in its outer shell.
• Hydrogen is in the first row and the first column of the periodic table.

Answer 1

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

• Hydrogen does not have any neutrons.

Hydrogen has an atomic number of 1, which means it has one proton. The most common isotope of hydrogen (protium) has no neutrons, so its atomic mass is also close to 1. Other isotopes of hydrogen (deuterium and tritium) have more mass due to the presence of neutrons, but the statement about hydrogen not having any neutrons accurately describes the most common isotope and its relationship between atomic number and mass.