Question 8 — Magnesium is essential for many - Questions at the end of the chapter - Chapter 8 - Journey Inside the Atom (Exploration)

Last updated at July 3, 2026 by

Question 8
Magnesium is essential for many biological processes, including muscle contraction. For an atom of magnesium with a mass number of 24 and atomic number 12, determine the number of (i) protons, (ii) neutrons, (iii) electrons, and also illustrate the arrangement of electrons in a magnesium atom.
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  • (i) Protons = atomic number = 12 .
  • (ii) Neutrons = A − Z = 24 − 12 = 12 .
  • (iii) Electrons = protons = 12 .
  • Arrangement (electronic configuration) = 2, 8, 2 (K=2, L=8, M=2).
Magnesium (Z 12, A 24) 12 protons, 12 neutrons and 12 electrons; electronic configuration 2, 8, 2.
Back to: 8.6 Mass Number
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