Explanation:
calcium ion is denoted as - Ca ²⁺
The number of electrons in a neutral atom of calcium = 20 , but since ,
it is charged atom ,
i.e. +2 , the number of electrons in calcium ion = 18 .
From , the question ,
The mass number = 41 ,
and
since ,
the mass number = number of protons + number of neutrons .
number of neutrons = mass number - number of protons
since ,
The number of protons for calcium ion = 20
number of neutrons = 41 - 20 = 21
Hence ,
number of neutrons = 21.