Atomic structure and bonding - Jamb Chemistry Past Questions and Answers

Question 41:

• JAMB 1987

An element Z, contained 90% of ¹⁶₈Z and 10% of Z¹⁸₁₈ its relative atomic mass is?

A. 16.0
B. 16.2
C. 17.0
D. 17.8

Question 42:

• JAMB 1988

Which of the following physical properties decreases across the Periodic Table?

A. Ionization potenial
B. Electron affinity
C. Electronegativity
D. Atomic radius

Question 43:

• JAMB 1988

The energy changes accompanying the addition of an electron to a gaseous atom is called?

A. First ionization energy
B. Second ionization energy
C. Electron affinity
D. Electronegativity

Question 44:

• JAMB 1989

The atomic radius of Li, Na and K are 1: 33A, 1. 54A and 1. 96A res pectively. Which of the following explaqins this gradation in atomic radius?

A. Electropositivity decreases from Li to Na to K
B. Electronegativity decreases from Li to Na to K
C. The number of the electron shells increases from Li to Na to K
D. The elements are in the same period

Question 45:

• JAMB 1989

Elements X and Y have electronic configurations 1s²2s²2p⁶ and 1s²2s²2p⁶3s²3p¹ respectively. When they combine, the formula of the compound formed is

A. XY
B. YX
C. X₂Y₃
D. Y₂X₃