Chemistry Past Questions and Answers

An element wil readily form an electrovalent compound if it electron configuration is

A 2, 8, 1
B 2, 8, 4
C 2, 8, 8
D 2, 8, 5

Question 32:

A heterogenous mixture can be defined as any mixture

A Of a solute nd a solvent
B Whose cmposition is uniform
C Whose composition is not uniform
D Formed by solids and liquids

Question 33:

The pressure of 100cm³ of oxygen at 35^oC is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature?

A 650 cm³
B 850 cm³
C 580 cm³
D 750 cm³

Question 34:

I. Treatment of cancerII. Detection of leakages in water mainsIII. Detection of the ages of ancient toolsIV. Preparation of drugs
Which combination of the above refers to the uses of radioactive isotopes?

A I and III
B I and II
C I, II and III
D I, II, III and IV

Question 35:

What is the valence shell electron configuration of the element with atomic number 17?

A 1s² 2s² 2p⁶ 3s² 3p⁴
B 1s² 2s² 2p⁶ 3s² 3p⁵
C 2s² 2p⁶
D 3s² 3p⁵