Question

i. The element lithium in the Modern Periodic Table with valency 1+

belongs to the ____________ Group.

ii. An element with Variable Valency is ______________ .

iii. There are __________ Groups and ____________ Periods in the Modern Periodic Table .

iv. (Halogens) – Fluorine, Chlorine , and Bromine belong to Group ____________ .

v. An example of divalent metal is ___________ .

vi. The black residue, obtained on heating copper carbonate ___________.

vii. The formula of Potassium Sulphide -______________.

viii. A metal which react – explosively with cold water is - _____________.

ix. The Atomicity of Noble Gases - _____________ .

x. The credit of the discovery of – Electrons , confers to _____________ .​

Answer 1

Answer:

1) Group 1

2) Manganese

3) 18 groups and 7 periods

4) Group 17 elements (Halogens)

5) Iron (II,III)

6) CuO (Copper Oxide)

7) K2S

8) Na & K

9) 0

10) J.J. Thomson

Explanation:

Answer 2

Answer:

1)alkali metal group

3)18,7

4)7A

7)K2s