JAMB Chemistry Past Questions & Answers - Page 283

1,411.

Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ3?

A.

Both are electrovalent

B.

Both are covalent

C.

XZ is electrovalent and YZ3 is covalent

D.

XZ is covalent and YZ3 is electrovalent

Correct answer is C

No explanation has been provided for this answer.

1,412.

Which of the following physical properties decreases down a group in the periodic table?

A.

Atomic radius

B.

Ionic radius

C.

Electropositivity

D.

Electronegativity

Correct answer is D

No explanation has been provided for this answer.

1,413.

The number of electrons in the valence shell of an element of atomic number 14 is?

A.

1

B.

2

C.

3

D.

4

Correct answer is D

No explanation has been provided for this answer.

1,414.

An increase in temperature causes an increase in the pressure of a gas because?

A.

it decreases the number of collision between the molecules

B.

the molecules of the gas bombard the walls of the container more frequently

C.

it increases the number of collision between the molecules

D.

it causes the molecules to combine

Correct answer is B

The temperature of the gas is proportional to the average kinetic energy of its molecules. Faster moving particles will collide with the container walls more frequently and with greater force. This causes the force on the walls of the container to increase and so the pressure increases.

1,415.

The shape of ammonia molecule is?

A.

trigonal planar

B.

octahedral

C.

square planar

D.

tetrahedral

Correct answer is A

No explanation has been provided for this answer.