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.

271.

The process or act of extracting a metal from its ore and refining it is called?

A.

Extraction

B.

Metal mining

C.

Mettallurgy

D.

Prospecting

Correct answer is C

Metallurgy, art and science of extracting metals from their ores and modifying the metals for use. 

272.

A binary compound of oxygen with another element is referred to as?

A.

Oxide

B.

Element

C.

Carbon

D.

Nitrogen

Correct answer is A

An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula.

273.

The reactions involving simultaneous oxidation and reduction?

A.

Automatic reactions

B.

Alternate reactions

C.

Reduction agency

D.

Redox reactions

Correct answer is D

Redox (reduction/oxidation) describes all chemical reactions in which atoms have an increase or decrease in oxidation number (oxidation state).

274.

A chemical process in which there is a gain of electrons is known as?

A.

Sublimation

B.

Reduction

C.

Oxidation

D.

Distillation

Correct answer is B

Reduction, any of a class of chemical reactions in which the number of electrons associated with an atom or a group of atoms is increased.

275.

An element having the atomic number 17 will resemble which of the following elements having atomic number as given below?

A.

33

B.

35

C.

18

D.

19

Correct answer is B

The Group 7 elements are called the halogens. They are placed in the vertical column, second from the right, in the periodic table . 

Chlorine (17), bromine(35) and iodine(53) are the first three of the Group 7 elements.