Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

3,092.

Which of the following is arranged in order of increasing electronegativity?

A.

Chlorine, aluminium, magnesium, phosphorus, sodium

B.

sodium, magnesium, aluminium, phosphorus, chlorine

C.

Chlorine, phosphorus, phosphorous, aluminium, magnesium, sodium

D.

Sodium, chlorine, phosphorus, magnesium, aluminium

Correct answer is B

No explanation has been provided for this answer.

3,093.

Which of the following represents the type of bonding present in ammonium chloride molecule?

A.

Ionic only

B.

Covalent only

C.

Ionic and dative covalent

D.

Dative covalent only

Correct answer is C

No explanation has been provided for this answer.

3,094.

The ions X- and Y+ are isoelectronic, each containing a total of 10 electrons.
How many protons are in the nuclei of the neutral atoms of X and Y respectively?

A.

10 and 10

B.

9 and 9

C.

11 and 9

D.

9 and 11

Correct answer is D

X- means one excess electron, hence 9 protons while Y +/- means one deficit electron hence 11 protons X and Y = 9 and 11

3,095.

The electronic configuration of an elements is 1s22s22p63s23p3. How many unpaired electrons are there in the element?

A.

5

B.

4

C.

3

D.

2

Correct answer is C

The atomic number of phosphorus is 15 and the 3p sublevel has three unpaired electrons.