<p>(A) 1s2 2s2 2p5 3s2 3p5
(B) 1s2 2s2 2p6 3s2 3p6
(C) 1s2 2s2 2p6 2d10 3s2 3p6
(D) 1s2 2s2 2p6 3s2 3p6 3d5
(E) 1s2 2s2 2p6 3s2 3p6 3d3 4s2</p>
<p>The ground-state configuration for the atoms of a transition element</p>
<p>Why is D, not E?</p>
<p>It is E… D is not possible.All transition metals in ground state have to have 4s2. I think your key is wrong.</p>
<p>Ok thanks, this key has been wrong before, so I’ll assume that E actually was right.</p>
<p>E is the correct answer.
But not all have 4s2. Chromium is an important exception with 3d5 4s1</p>
<p>^ Yes was just giving a quick reply, sorry! Another exception is Cu</p>
<p>It has to have 4s2</p>