WAEC Past Questions and Answers - Page 1622

8,106.

P,Q,R and S are metals in the same group in the Periodic Table but in periods 3,4, 5 and 6 respectively which of them loses electrons least readily?

A.

P

B.

C

C.

R

D.

S

Correct answer is D

It is because the tendency to loss electrons increases with an increase in atomic size and atomic increase down the group

8,107.

Given that the electronic configuration of an element X is 1s22s22p63s 23p4, it can be deduced that X

A.

belongs to group VI in the Periodic Table

B.

belongs to periodic Table

C.

contains 3 unpaired electrons in the ground state

D.

has atomic number 27

Correct answer is A

No explanation has been provided for this answer.

8,108.

What is the mass number of an element if its atom contains 10 protons, 10 electrons and 12 neutrons?

A.

32

B.

22

C.

20

D.

10

Correct answer is B

No explanation has been provided for this answer.

8,109.

Allotropes of an element differ in their

A.

physical properties

B.

chemical properties

C.

mass numbers

D.

electronic configuration

Correct answer is A

No explanation has been provided for this answer.

8,110.

A plastic which cannot be softened by heat is described as

A.

thermosetting

B.

non-biodegradable

C.

thermoplastic

D.

malleable

Correct answer is A

No explanation has been provided for this answer.