What are rubies and sapphires chemically known as?

Options

(a)

Silicon dioxide

(b)

Aluminum oxide

(c)

Lead tetroxide

(d)

Boron nitride

Answer

(B)

Science and Technology › Chemistry

2008

Mixture of which one of the following pairs of gases is the cause of occurrence of most of the explosions in mines?

Options

(a)

Hydrogen and oxygen

(b)

Oxygen and acetylene

(c)

Methane and air

(d)

Carbon dioxide and methane

Answer

(C)

Science and Technology › Chemistry

2008

Which one of the following pairs of metals constitutes the lightest metal and the heaviest metal, respectively?

Options

(a)

Lithium and mercury

(b)

Lithium and osmium

(c)

Aluminum and osmium

(d)

Aluminum and mercury

Answer

(B)

Science and Technology › Chemistry

2008

What is the pH level of blood of a normal person?

Options

(a)

4.5-4.5

(b)

6.45-6.55

(c)

7.35-7.45

(d)

8.25-8.35

Answer

(C)

Science and Technology › Chemistry

2003

Regarding the atom of a chemical element, the magnetic quantum number refers to:

Options

(a)

Orientation

(b)

Shape

(c)

Size

(d)

Spin

Answer

(A)