<p>From practice test #2</p>
<li> Consider the following orderings and decide which of them give(s) a correct trend in ionization energy:</li>
</ol>
<p>I. Al < Si < P < Cl
II. Be < Mg < Ca < Sr
III. I < Br < Cl < F
IV. Na+ < Mg2+ < Al3+ < Si4+</p>
<pre><code>(A) I only
(B) III only
(C) I and II only
(D) I and IV only
(E) I, III, and IV only
</code></pre>
<p>The key says it’s D, but I contend that it’s E. Input?</p>
<p>III seems right to me (although I am far from being an expert).
Atomic radius increases as you go down the table and it takes less energy to remove an electron since the bigger atoms hold their outermost electrons farther away from the protons in the nucleus.
It works for III.</p>
<p>I saw the same mistake... yes III should be correct as well.</p>
<p>I also think II is right. Don't worry, I found a lot of mistakes in the sparknotes tests or their solutions, not only in bio. I hope mistakes like that won't appear in the real test</p>
<p>I agree with OP, but to the previous poster #2 is incorrect. The "less than" signs would have to be reversed in order for it to be correct. Sr has the LEAST highest ionization energy becasue it has the highest electron shielding and therefore lower positive pull towards the nucleus, so it would take LESS energy to dismantle 1 electron.</p>
<p>Yah i noticed that too... the SAT II sparknotes book has a lot of problems, like the list of answers after the second practice test is wrong, use the answers given in the explanations if correcting</p>