1)Zinc is non-ductile and non-malleable.

2) Sodium & Potassium r soft solids.

3) Lead has low melting point.

STILL Y THESE R CONSIDERED AS "METALS"?

Hi,

 Zinc, sodium, potassium and lead are classified as metals on the basis of their tendency to give away the electrons. The properties ductility, malleability, hardness, etc are generally seen properties of most metals but absence of any of these properties does not restrict them to be metal. They are metals by virtue of their tendency to act as electron as electron donor.

 Hope it helps.

Cheers!