An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is:

1. 17
2. 11
3. 18
4. 20

Select the correct answer from A, B, C and D : The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is:

(A) 1 : 2

(B) 1 : 0.01

(C) 1 : 1

(D) 0.01 : 1

[H = 1, O = 16]

The particles present in strong electrolytes are:

1. only molecules
2. mainly ions
3. ions and molecules
4. only atoms.

The aim of the Fountain Experiment is to prove that:

1. HCI turns blue litmus red
2. HCI is denser than air
3. HCl is highly soluble in water
4. HCl fumes in moist air.