Which of the following metals is soft enough to be cut easily with a knife?

Generally,non-metals are not lustrous. Which of the following non-metal is lustrous?

Name the following:
$(a)$ $A$ metal that can be cut with a knife.
$(b)$ $A$ metal that is liquid at room temperature.
$(c)$ $A$ metal that has $3$ valence electrons.

Give reasons for the following:
$(a)$ School bells are made of metals.
$(b)$ Electrical wires are made of copper.

Name a non-metal which is lustrous and a metal which is non-lustrous.

Name the following:
$(a)$ $A$ metal which is preserved in kerosene.
$(b)$ $A$ lustrous coloured non-metal.
$(c)$ $A$ metal which can melt while kept on palm.
$(d)$ $A$ metal which is a poor conductor of heat.