Question

7. What information do you get
from the figures about the atomic
number, mass number and valency
of atoms X, Y and Z? Give your
answer in a tabular form. (3)​

Answer 1

Answer:

there is no diagram of atom so can't tell you

Answer 2

Answer:

Valency is the combining capacity of one element with the other. If the number of valence electrons are 1, 2, 3, 4 then the valency is the same as the number of electrons. If the number of electrons are more than 4 then the valency is 8-(no. of outermost electrons). The electronic configuration of X is 2, 3. The electronic configuration of Y is 2, 6. The electronic configuration of Z is 2, 8, 5. The atomic number is the number of protons and the mass number is the sum of both protons and neutrons.

X

Y

Z

Valency (no. of electrons in outer shell that can be lost)

3

2

3, 5

Atomic no.(no. of protons)

5

8

15

Mass no.(sum of protons and neutrons)

11

18

31