RBSE Guide
Science ·Class 9 Science

An atom with an atomic number of 26 has 56 nucleons. Find out its number of electrons. Class 9

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· Jul 04, 2026 · Reviewed & updated Sep 17, 2026 · 1 min read

An atom with an atomic number of 26 has 56 nucleons. Find out its number of electrons. Class 9


Question 1.

An atom with an atomic number of 26 has 56 nucleons. Find out its number of electrons, protons and neutrons. (Page 150) Class 9

Answer:

  1. Atomic number (Z) = 26, so number of protons = 26.
  2. Since the atom is electrically neutral, number of electrons = number of protons = 26.
  3. Number of nucleons (mass number A) = 56.
  4. Number of neutrons = A - Z = 56 — 26 = 30.

Answer: Protons = 26, Electrons = 26, Neutrons = 30. (This element is Iron, Fe.)


Question 2.

The nucleus of an atom contains 20 protons. If its mass number is 41, find the number of neutrons in it. (Page 150) Class 9

Answer:

  1. Number of protons = 20, Mass number (A) = 41.
  2. Number of neutrons = A - number of protons = 41 - 20 = 21.

Answer: The atom has 21 neutrons.