Which of the following is the number of neutrons in the most common isotope of hydrogen?

• A. 3
• B. 1
• C. 2
• D. 0

Answer: (D)

Verified step by step guidance

1. Recall that the most common isotope of hydrogen is protium, which has an atomic number of 1. The atomic number represents the number of protons in the nucleus.
2. Understand that the number of neutrons in an isotope is calculated by subtracting the atomic number (number of protons) from the mass number (total number of protons and neutrons).
3. For the most common hydrogen isotope, the mass number is 1 because it consists of only one proton and no neutrons.
4. Apply the formula for neutrons: \(\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}\).
5. Substitute the values: \$1 - 1 = 0$, which means the most common hydrogen isotope has zero neutrons.