Multiple choice

Which of the following is a condition for existence of a radioactive element?

  1. The number of protons and neutrons are nearly equal.

  2. The number of protons exceeds the number of neutrons.

  3. The number of neutrons exceeds the number of protons.

  4. The number of protons exceeds the number of electrons.

  5. The number of electrons exceeds the number of neutrons.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the number of neutrons exceeds the number of protons in a nucleus, it becomes unstable or radioactive.