Question 12 — An atom has 79 protons - Questions at the end of the chapter - Chapter 8 - Journey Inside the Atom (Exploration)

Last updated at July 16, 2026 by

Question 12
An atom has 79 protons and a mass number of 197. Calculate (i) the number of neutrons, and (ii) the number of electrons.
View Answer Hide Answer
  • (i) Neutrons = A − Z = 197 − 79 = 118 .
  • (ii) Electrons = protons = 79 (neutral atom). This element is gold, Au.
Neutrons and Electrons
Neutrons equal A minus Z equals 197 minus 79 equals 118; electrons equal protons equals 79.
Back to: 8.6 Mass Number
Remove Ads
Teachoo · Class 9 Explore Class 9
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant with 16+ years of practical experience and 20+ years of teaching experience. He teaches Science, Economics, Accounting and English at Teachoo using clear explanations and exam-focused methods students can trust.

For faster and distraction-free study, students can choose Teachoo Black.