WAEC Chemistry Past Questions & Answers - Page 103

511.

A hydrogen atom which has lost an electron contains

A.

one proton only

B.

one neutron only

C.

one proton and one neutron

D.

one proton, one electronic and one neutron

Correct answer is A

No explanation has been provided for this answer.

512.

The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?

A.

16

B.

17

C.

18

D.

19

Correct answer is C

Cl = 17 = 2, 8, 7.

Cl ion = Cl\(^-\) = 2, 8, 8 = 18.

513.

The atom of an element X is represented as \(^y_z X\). The basic chemical properties of X depend on the value of

A.

Y

B.

Z

C.

Y - Z

D.

Z - Y

Correct answer is B

No explanation has been provided for this answer.

514.

If the relative molecular mass of an element is not a whole number, it can be deduced that the element is

A.

naturally radioactive

B.

abundant in nature

C.

a transition metal

D.

an isotopic mixture

Correct answer is D

No explanation has been provided for this answer.

515.

The oxide from electric power station is

A.

carbon (IV) oxide

B.

copper (ll) oxide

C.

nitrogen (IV) oxide

D.

sulphur (IV) oxide

Correct answer is C

 Nitric oxide is an important component of the air pollution generated by automotive engines and thermal power-generating plants.

sulphur dioxide may also be produced in case of fuel containing sulphur, Nigeria crude is sulphur free,