(a) List in tabular form three chemical properties on the basis of which we can differentiate between a metal and a non-metal.(b) Give reasons for the following:(i) Most metals conduct electricity well.(ii) The reaction of iron (III) oxide [Fe₂O₃] with heated aluminium is used to join cracked machine parts.

S.No.	Metals	Nonmetals
1	Metals react with oxygen to form basic oxides. $2Mg + O_2 → MgO$	Nonmetals react with oxygen to form Acidic or neutral oxides. $C + O_2 → CO_2$
2	Metals react with water to produce metal hydroxide and hydrogen gas. $Mg + H_2O → Mg(OH)_2 + H_2O$	Nonmetals do not react with water.
3	Metals form positively charged ions by losing electrons.	Nonmetals form negatively charged ions by gaining electrons.

 b (i) The outer electrons of metal atoms are not tied to any one atom. Therefore, these electrons are free to move within the structure of metal when an electric current is applied. So, metals make good conductors. For example, Na has an electronic configuration of 2, 8, 1 i.e. it has one free electron to conduct electricity.

(ii) $Fe_2O_3 (s) + 2Al (s) → Al_2O_3 (s) + 2Fe (l) + Heat$

The reaction taking place between Fe2O3and aluminium is a thermite reaction.

This reaction is an exothermic reaction the reaction produces a large amount of heat due to which iron metal is produced in a molten form which is used to join the tracks.