Question

1. Elements of heating devices are made up of alloys because

a) They have high melting points

b) They have high resistivity

c) They do not oxidize readily

d) All the above

2. The steps involved in the extraction of metals from carbonate ores

a) Roasting, oxidation, reduction, purification

b) Calcination, oxidation, reduction, purification

c) Electrolysis of molten ore, oxidation, reduction, purification

d) Roasting, calcination, electrolysis of molten ore, purification

3. The metals which do not react with water like Silver and Gold are

a) Na, Cu

b) Fe, Pb

c) Cu, Pb

d) Pt, K

4. Which of the following is a plant hormone?

a) Insulin

b) Thyroxin

c) Oestrogen

d) Cytokinin​

Answer 1

Answer:

Q1a: because they have high melting points