<p>Consider the following orderings and decide which of them give(s) a correct trend in ionization energy:</p>
<p>I. Al < Si < P < Cl
II. Be < Mg < Ca < Sr
III. I < Br < Cl < F
IV. Na+ < Mg2+ < Al3+ < Si4+</p>
<p>The answer is I and IV. But isn't statement III correct as well because you are going UP within the group, so ionization energy should increase.</p>
<p>here's what SN said</p>
<p>Statement II is backward since IE decreases as you move down a family, and III is backward for the same reason.</p>
<p>This explanation has to be incorrect because statement III isn't moving down a family, its moving UP.</p>
<p>am i right or am i wrong?</p>