WAEC Chemistry 2020 Paper

Concept:Across a period, electronegativity increases from left to right.Explanation:The elements Na, Mg, Al, Si, and P are all in the third period of the periodic table.Electronegativity increases across a period as nuclear charge increases.Therefore, the correct increasing order is: $\mathrm{Na} < \mathrm{Mg} < \mathrm{Al} < \mathrm{Si} < \mathrm{P}$.So, the decreasing order is the reverse: $\mathrm{P} > \mathrm{Si} > \mathrm{Al} > \mathrm{Mg} > \mathrm{Na}$.This matches option D.Answer:D. P, Si, Al, Mg, Na