Which metal is used in Wurtz synthesis?

When a certain alkane is mixed with chlorine and irradiated with ultraviolet light,only one monochloroalkane is formed. This alkane is likely to be:

The number of shared pairs of electrons in propane is

The interaction that causes the most instability in the boat conformation of cyclohexane is .......

The alkane formed on heating sodium butanoate with sodalime is

Select the chain propagation steps in the free-radical chlorination of methane.
$(1) \, Cl_2 \to 2Cl^{\bullet}$
$(2) \, Cl^{\bullet} + CH_4 \to CH_3Cl + H^{\bullet}$
$(3) \, Cl^{\bullet} + CH_4 \to CH_3^{\bullet} + HCl$
$(4) \, H^{\bullet} + Cl_2 \to HCl + Cl^{\bullet}$
$(5) \, CH_3^{\bullet} + Cl_2 \to CH_3Cl + Cl^{\bullet}$