Atomic Structure and Chemical Bonding — CHEMISTRY STD 9 — Question

What are the following group known as?
Group 1

An element A has 2 electrons in its fourth shell. State:
its atomic number

Define
Henry's law

Give reason:
Inert gases do not form compounds.

Write a balanced equation for the reaction named metal with (i) boiling water (ii) steam.

Identify the following substance:
An alkaline gas A which gives dense white fumes with hydrogen chloride.

The atomic number and mass number of sodium are 11 and 23 respectively. What information is conveyed by this statement?

What do you understand by ppm?

Write the balanced chemical equation of the following reaction.
sodiumchloride+manganese dioxide+sulphuricacid → sodium hydrogensulphate+manganesesulphate+water+chlorine.

Explain why:
If distilled water is kept in a sealed bottle for a long time, it leaves etchings on the surface of the glass.