Question

25. A metal is strongly heated in presence of air to form a
black mass. So the metal is
(a) Potassium
(b) Platinum
(c) Copper
(d) Zinc​

Answer 1

Answer:

c

Explanation:

copper and air

black mass

Answer 2

(c) A metal is strongly heated in presence of air to form a black mass. So the metal is copper.

Explanation:

• Copper reacts with oxygen to form the black mass called copper oxide.
• When the copper is heated, it usually turns black.
• The symbol for copper is Cu.
• $2 Cu + O$₂→$2 CuO$ , is the chemical equation that takes place.
• 29 is the atomic number of copper and it is the soft, ductile metal.
• Copper has high thermal and electrical conductivity.
• Copper is used for generators, motors, television, wires etc.