Which of the following statement is correct regarding metals and non-metal?

(1) All metals are brittle.
(2) All non-metals are ductile.
(3) Generally metals are ductile.
(4) Non-metals are good conductor of electricity.

Which of the following always contains mercury as one of the constituent ?

(1) Stainless steel
(2) Solder
(3) Duralumin
(4) Zinc Amalgam

An element which shows allotrophy when burnt in air gives a gas with characteristic smell. The gas turns blue litmus red and is used as an insecticide. The element is

(1) C
(2) N
(3) P
(4) S

Pick up the incorrect pair of metal-ore from the following

(1) Ag – Galena
(2) Mg – Carnallite
(3) Sn – Cassiterite
(4) Hg – Cinnabar

The impurity present in the ore is called ..........

(1) gangue
(2) flux
(3) slag
(4) mineral