WAEC Chemistry Past Questions & Answers - Page 206

1,026.

The presence of unpaired electrons in an atom of a transition metal gives rise to

A.

paramagnetism

B.

nalleability

C.

ductility

D.

shiny appearance

Correct answer is A

No explanation has been provided for this answer.

1,027.

The atom of an element X combines with aluminium (13AI)?

A.

AIX 2

B.

AI 2X

C.

AI2X 2

D.

AI 2X 3

Correct answer is D

No explanation has been provided for this answer.

1,028.

Elements which belong to the same group in the Periodic Table are characterized by

A.

difference of +1 in the oxidation numbers of successive members

B.

presence of the same number of outermost electrons in the respective atoms

C.

difference of 14 atomic mass units between successive members

D.

presence of the same number of electron shells in the respective atoms

Correct answer is B

No explanation has been provided for this answer.

1,029.

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

1,030.

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.