Question

What is meant by atomic number and mass number of an atom? Two atoms X and

Y are denoted as follows. Find out the atomic number and valency of X and Y.
(i) 20
10 X (ii) 27
13 Y

Answer 1

Step-by-step explanation:

The atomic number, mass number, and valency of the atoms X, Y and Z are given on the table below:-

X

Y

Z

Atomic No.

5

8

15

Mass no.

11

18

31

Valency

3

2

3,5