Question

The number of electrons, protons and neutrons in an atom whose atomic number is 11 and mass number 23 will be:

• A. $11,11,12$
• B. $11,12,11$
• C. $12,11,11$
• D. $23,11,23$

Answer 1

The correct option is A $11,11,12$

Mass number $=$ 23 and atomic number $=$ 11.

Atomic number $=$ Number of electrons $=$Number of protons $=11$.

Number of neutrons $=$ Mass number $-$ atomic number $=(23-11)=12$.

Hence, option A is correct.