56.

The metal that is usually extracted from sea water is

A. Ca B. Na
C. K D. Mg
Answer:D
Explanation: No answer description available for this question.

57.

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:C
Explanation: No answer description available for this question.

58.

The inert gases are ____ in water

A. sparingly soluble B. insoluble
C. soluble D. None of these
Answer:A
Explanation: No answer description available for this question.

59.

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:C
Explanation: No answer description available for this question.