Atomic structure and bonding - Jamb Chemistry Past Questions and Answers

Question 51:

• JAMB 1990

Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.
The relative abundance of the isotope of mass number 37 is?

A. 20
B. 25
C. 50
D. 75

Question 52:

• JAMB 1990

Changes in the physical in the scheme above.The letter X,Y and Z respectively represent

A. Sublimation, condensation and freezing
B. Sublimation, vapourization and solidification
C. Freezing, condensation and sublimation
D. Evaporation, liquefaction and solidification

Question 53:

• JAMB 1991

Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell). Which of the following statements is FALSE? The compound formed?

A. Has formula XY
B. Is likely to be ionic
C. Contains X²⁺ ions
D. Contains Y^- ions

Question 54:

• JAMB 1991

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

Question 55:

• JAMB 1991

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