CHEMISTRY · Multi-part · AP · Chemistry · Atomic Structure and Properties · Atomic Structure and Properties
Problem
Four unknown gaseous elements—W, X, Y, and Q—each in the first three periods of the periodic table, have the successive ionization energies (in kJ mol⁻¹) shown below.
Element W 500 4560 6910 9540 13400
Element X 900 1760 14850 21000 25900
Element Y 495 4560 6910 9540 13400
Element Q 800 2420 3650 25000 32600
IE₁ IE₂ IE₃ IE₄ IE₅
Respond to the prompts that follow.
(a) For each element, determine between which two successive ionizations (IEₙ and IEₙ₊₁) the greatest increase in ionization energy occurs.
(b) For element Q, use the data from part (a) to deduce the most probable oxidation state it adopts when forming ionic compounds with nonmetals in the third period. State your reasoning clearly.
(c) Identify which element (W, X, Y, or Q) is most likely to be magnesium. Justify your answer with reference to both the numerical data and periodic trends.