Atomic Structure and Chemical Bonding — CHEMISTRY STD 9 — Question

What do you observe? When
Barium chloride is added to sodium sulphate solution

Give an example of a reaction where the following are involved
Heat

Whenever a gas is subjected to electric discharge at low pressure, cathode rays and positive rays formed. what does the formation of these rays tell us about the nature of atoms in he gas?

The following table shows electronic configuration of elements P, O, R and S. From the list, choose inert gases and give a reason/reasons for your choice:

Element	Electronic configuration
	K L M N
P	2, 8, 2, _
Q	2, _ , _, _,
R	2, 8, 18, 8,
S	2, 8, 8, _

The position of elements A, B, C, D and E in the periodic table are shown below:

Group 1	Group 2	Group 17	Group 18
			D
	B	C
A			E

Which is larger in size (i) D or E (ii) B or C

Explain the terms:
Solvent

Name a noble gas which has less than 8 electrons in its valence shell. What is the atomic number of this gas?

Gas equation