Complete the following tables:

Explanation

For nitrogen atom. No. of electrons = 7(Given)
No. of neutrons = 7 (Given)
No. of protons = Z = 7 (` :'` atom is electrically neutral)
Atomic number = Z = 7
Mass No. (A) = No. of protons + No. of neutrons `= 7 + 7 = 14`
For calcium ion. No. of neutrons = 20 (Given) , Atomic No. (Z) = 20 (Given)
`:.` No. of protons = Z = 20, No. of electrons in calcium atom = Z = 20
But in the formation of calcium, two electrons are lost from the extranuclear part according to the equations `Ca rarr Ca^(2+) + 2e^(-)` but the composition of the nucleus remains unchanges.
`:.` No. of electrons in calcium `= 20 - 2 = 18`
Mass number (A) = No. of protons + No. of neutrons `= 20 + 20 + 40`
For oxygen atom. Mass number (A) = No. of protons + No. of neutrons = 16(Given)
Atomic No. (Z) = 8 (Given)
No. of protons = Z = 8, No. of electrons = Z = 8, No. of neutrons `= A - Z 16 - 8 = 8`
For bromide ion. In the formation of bromide ion, one electron is added to the extranuclear part of the bromine atom according to the equation `Br + e^(-) rarr Br^(-)` but the composition of the nucleus remains unchanged.
Since the no. of electrons in bromide ion = 36 (Given)
No. of electrons in bromine atom `= 36 - 1 = 35`
Further, since in the above reaction, nucleus of the bromine atom remains unchanged.
`:.` No. of protons in the bromide ion = No. of protons in the bromine atom = 35
Putting the value of the various vacant place as calculated above, in the table, we have