People use a variety of methods to wash clothes. Usually, after adding the soap, they 'beat' the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?

Ethane, with the molecular formula C₂H₆, has

1. 6 covalent bonds
2. 7 covalent bonds
3. 8 covalent bonds
4. 9 covalent bonds

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that

1. the food is not cooked completely
2. the fuel is not burning completely
3. the fuel is wet
4. the fuel is burning completely

Explain the nature of the covalent bond using the bond formation in CH₃Cl.