They react with oxygen to form basic oxides.

$4 Na + O _{2} \longrightarrow 2 Na _{2} O$

These have ionic bonds.

They react with oxygen to form acidic or neutral oxides.

$C + O _{2} \longrightarrow CO _{2}$

These have covalent bonds.

They react with water to form oxides and hydroxides. Some metals react with cold water, some with hot water, and some with steam.

$2 Na +2 H _{2} O \longrightarrow 2 NaOH + H _{2} \uparrow$

They react with dilute acids to form a salt and evolve hydrogen gas. However, $Cu ,\, Ag ,\, Au , \,Pt ,\,Hg$ do not react.

$2 Na +2 HCl \longrightarrow 2 NaCl + H _{2} \uparrow$

They react with the salt solution of metals. Depending on their reactivity, displacement reaction can occur.

$CuSO _{4}+ Zn \longrightarrow ZnSO _{4}+ Cu$

They act as reducing agents (as they can easily lose electrons).

$Na \longrightarrow Na ^{+}+ e ^{-}$

These act as oxidising agents (as they can gain electrons).

$Cl _{2}+2 e ^{-} \longrightarrow 2 Cl ^{-}$