Complete the following table :

Atomic number	Mass number	No. of electrons	No. of protons	No. of neutrons
9	A	B	C	10
D	24	E	12	F

A, B, C, D, E, F respectively are :

Correct Option: 19, 9, 9, 12, 12, 12

To complete the table, let us review the fundamental relationships between atomic number, mass number, protons, neutrons, and electrons in a neutral atom:

1. Atomic Number (Z): Represents the total number of protons in the nucleus of an atom. In a neutral atom, the number of electrons is equal to the number of protons.
$\text{Atomic number}=\text{No. of protons}=\text{No. of electrons}$

2. Mass Number (A): Represents the total number of protons and neutrons in the nucleus of an atom.
$\text{Mass number}=\text{No. of protons}+\text{No. of neutrons}$

Now, let us find the values of A, B, C, D, E, and F step-by-step.

For the first row:
Given: Atomic number = 9, No. of neutrons = 10.

• Since Atomic number = 9, the number of protons (C) and the number of electrons (B) in a neutral atom must both be 9.
$\text{C}=9$
$\text{B}=9$

• The Mass number (A) is the sum of protons and neutrons:
$\text{A}=\text{No. of protons}+\text{No. of neutrons}=9+10=19$

So, for the first row: A = 19, B = 9, C = 9.

For the second row:
Given: Mass number = 24, No. of protons = 12.

• Since Atomic number equals the number of protons:
$\text{D}=12$

• In a neutral atom, the number of electrons (E) equals the number of protons:
$\text{E}=12$

• The number of neutrons (F) is obtained by subtracting the number of protons from the mass number:
$\text{F}=\text{Mass number}-\text{No. of protons}=24-12=12$

So, for the second row: D = 12, E = 12, F = 12.

Summary of values:
A = 19
B = 9
C = 9
D = 12
E = 12
F = 12

Therefore, A, B, C, D, E, F respectively are 19, 9, 9, 12, 12, 12.