Waec Chemistry 2017 Past Questions and Answers

Question 11:

• WAEC 2017

The reason for the decrease in the atomic size of elements across a period is that

A. Nuclear charge increases while the outermost electrons are drawn closer to the nucleus
B. Nuclear charge decreases while the outermost electrons are drawn closer to the nucleus
C. Valence electrons increase across the period while the valence shell remains constant
D. Nuclear charge decreases while the distance of the valence shell from the nucleus is increasing

Question 12:

• WAEC 2017

The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is

A. +2
B. +3
C. +4
D. +5

Question 13:

• WAEC 2017

Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements?

A. Na, Al, P, Cl
B. Cl, P, Al, Na
C. Na, P, Cl, Al
D. Al, Na, P, Cl

Question 14:

• WAEC 2017

Which of the following metals has the strongest metallic bond?

A. \(_{13}Al\)
B. \(_{19}K\)
C. \(_{12}Mg\)
D. \(_{11}Na\)

Question 15:

• WAEC 2017

Which of the following substances does not have van der Waals' forces?

A. Copper
B. Graphite
C. Neon
D. Iodine crystals