The periodic table and periodicity of elements - Jamb Chemistry Past Questions and Answers

Question 16:

• JAMB 1985

The atomic number of an element whose cation, X²⁺, has the ground state electronic configuration 1s²2s²2p⁶3s²2p⁶ is?

A. 16
B. 18
C. 20
D. 22
E. 24

Question 17:

• JAMB 1985

Figure 1 above shows part of the periodic Table which of the elements belongs to the p-block?

A. S, T and U
B. V, W and X
C. S and T only
D. P, Q and R
E. V, W, X and S

Question 18:

• 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 19:

• 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 20:

• 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