a) State the reason for addition of caustic alkali to bauxite ore during purification of bauxite.
b) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition

The electronic configuration of metal A is 2,8,18,1.
The metal A when exposed to air and moisture forms B a green layered compound. A with con. H₂SO₄ forms C and D along with water. D is a gaseous compound. Find A,B,C and D.

Explain smelting process.

Explain the salient features of periods in the modern periodic table.

Explain the salient features of groups in the modern periodic table.

How will you predict the nature of chemical bonds using electronegativity values?

How are magnetic ores separated from non magnetic impurities? Explain.

How is Bauxite ore concentrated?

Metal A belongs to period 3 and group 13. A in red hot condition reacts with steam to form B. A with strong alkali forms C. Find A, B and C with reactions.

Name the acid that renders aluminium passive. Why?

a) Identify the bond between H and F in HF molecule.
b) What property forms the basis of identification?
c) How does the property vary in periods and in groups?