WAEC Physics Past Questions & Answers - Page 183

911.

A tuber of cassava can be processed into powder. This explains the fact that

A.

matter can change sponteneously from one state to another

B.

matter cannot be destroyed

C.

force is required to change matter from one state to another

D.

matter is made up of tiny particles

Correct answer is D

No explanation has been provided for this answer.

913.

Which of the following materials is used to control the rate of neutron production in a nuclear reactor?

A.

boron rods

B.

concrete shield

C.

graphite rods

D.

uranium rods

Correct answer is A

No explanation has been provided for this answer.

914.

Which of the following is usually used to cause fission in an atomic reactor?

A.

Alpha particles

B.

beta particles

C.

electrons

D.

Neutrons

Correct answer is D

No explanation has been provided for this answer.

915.

If a radioactive atom emits a beta particle, Its mass number

A.

increases by one

B.

remains the same

C.

decreases by one

D.

increases by two

Correct answer is B

No explanation has been provided for this answer.