JAMB Chemistry Past Questions & Answers - Page 29

141.

The nucleus of an atom consists of?

A.

Electrons and neutrons

B.

Electrons and protons

C.

Protons and neutrons

D.

None of the above

Correct answer is C

An atom nucleus is made up of protons and neutrons.

An electron is a negatively charged subatomic particle that orbits the nucleus of an atom.

142.

The metal used to recover copper from a solution of copper sulphate is?

A.

Na

B.

Ag

C.

Hg

D.

Fe

Correct answer is D

The ideal metals to use for the task of recovering copper from an aqueous solution of copper sulphate are metals that are stronger reducing agents than copper but not reactive enough to react with the water that the solution consists of.

 Zinc, Aluminium, Iron are relatively inexpensive and being unreactive on exposure to water.

143.

The nucleus of a hydrogen  atom consist of a?

A.

1 proton only

B.

1 proton, 2 neutron

C.

1 neutron only

D.

1 electron only

Correct answer is A

The hydrogen atom is the simplest of all atoms: it consists of a single proton and a single electron

144.

The heat required to raise the temperature of the body by 1k is called?

A.

Specific heat

B.

Thermal capacity

C.

Water equivalent

D.

None of the above

Correct answer is B

Heat capacity or thermal capacity: The amount of heat to be supplied to an object to produce a unit change in its temperature(1k).

145.

The most abundant rare gas in the atmosphere is?

A.

He

B.

Ne

C.

Ar

D.

Xe

Correct answer is C

The most abundant naturally occurring gas is Nitrogen (N2), which makes up about 78% of air. Oxygen (O2) is the second most abundant gas at about 21%. The inert gas Argon (Ar) is the third most abundant gas. 

Argon is the most abundant rare gas in the atmosphere. It is represented by the symbol Ar. The atomic number of Ar is 18.