Question 15 — In an atom, there are - Questions at the end of the chapter - Chapter 8 - Journey Inside the Atom (Exploration)

Last updated at July 16, 2026 by

Question 15
In an atom, there are 12 protons and 12 neutrons in the nucleus. Now, imagine that all the electrons are replaced with some hypothetical particles that have the same charge as electrons but are 500 times heavier. What effect will this replacement have on the atom’s: (i) Atomic number (ii) Atomic mass (iii) Mass number (iv) Overall charge
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  • (i) Atomic number — unchanged (still 12; depends only on protons).
  • (ii) Atomic mass — increases (the new particles are much heavier than electrons).
  • (iii) Mass number — unchanged (counts only nucleons: protons + neutrons).
  • (iv) Overall charge — unchanged, still neutral (the charge of each particle is the same as an electron).
Heavier Electrons Charge unchanged: same Z, same overall charge Mass number counts only nucleons But the atomic mass increases
Back to: 8.3 What Components Contribute to the Mass of an Atom?
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