Exercise 3

Question 21 :

The method of concentrating the ore which makes use of the difference in density between ore and impurities is called

A). liquation
B). leaching
C). levigation
D). magnetic separation
Answer : Option C

Question 22 :

The inert gases are ____ in water

A). sparingly soluble
B). insoluble
C). soluble
D). None of these
Answer : Option A

Question 23 :

The molecular formula of phosphorous is

A). P1
B). P2
C). P3
D). P4
Answer : Option D

Question 24 :

The names of the scientists, Newlands, Mendeleev, and Meyer are associated with the development of

A). atomic structure
B). metallurgy
C). periodic table of contents
D). discovery of elements
Answer : Option C