Multiple choice general knowledge math & puzzles

When radium (atomic number 88) emits an alpha particle, the resulting nucleus has atomic number.

  1. 92

  2. 90

  3. 88

  4. 86

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

An alpha particle consists of 2 protons and 2 neutrons. When a nucleus emits an alpha particle, its atomic number decreases by 2. Radium (88) minus 2 protons results in an atom with atomic number 86, which is Radon.