Multiple choice general knowledge science & technology

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

When a nucleus emits an alpha particle, it loses 2 protons (and 2 neutrons). An alpha particle is essentially a helium-4 nucleus, so the atomic number decreases by 2. Radium has Z=88, so after alpha decay the new nucleus has Z=88-2=86.

Keep practicing — related questions