gneet

Study Companion

For more NEET and AIIMS mcq on Structure of Atom Visit www.gneet.com
Question
Q252) Atomic number and mass number of an element M are 25 and 52 respectively. The number of electrons, protons and neutrons in M2+ ion are respectively



SOLUTION

Atomic number = 25
Mass number = 52
Number of proton = Atomic number = 25
Number of neutron = (Mass number – Atomic number)
52 – 25 = 27
Number of e– = Number of protons,
but M2+ ion means 2e– are removed
 Number of e– = Number of protons – 2
= 25 – 2 = 23
Answer:(d)