Chemistry - Study Mode

[#151] Which among the following is liquid non-metal ?
Correct Answer

(B) Bromine

Explanation

Solution: Bromine is a liquid non-metal.

[#152] Metal are good conductors, because
Correct Answer

(A) They contain free electrons

Explanation

Solution: Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.

[#153] The first metal used by a man was
Correct Answer

(A) Copper

Explanation

Solution: The first metal used by a man was copper.

[#154] White phosphorus is generally kept under
Correct Answer

(B) Water

Explanation

Solution: White phosphorus is highly reactive, and spontaneously ignites at about 30°C in moist air. It is usually stored under water, to prevent exposure to the air.

[#155] Which metal is extracted from sea water?
Correct Answer

(B) Magnesium

Explanation

Solution: The elements dissolved in sea water have been commercially extracted in many quantity. They are sodium and chlorine in the form of common salt, magnesium and some of its compounds, and bromine.