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adf89812
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- Is this stackexchange.com answer bad?
There was a post on stackexchange.com explaining the trend in melting/boiling points of first series transition elements.
https://chemistry.stackexchange.com/questions/4766/melting-and-boiling-points-of-transition-elements
The specific question was:
The melting and boiling points of transition elements increase from scandium (1530 ∘C1530 ∘C) to vanadium (1917 ∘C1917 ∘C). They increase because as we go across the group, we have more unpaired (free) electrons. But at chromium (1890 ∘C1890 ∘C) however, the melting point decreases even though it has more unpaired electrons than the previous atoms. Why does this happen?
Part of the answer I'm confused about is "In half-filled subshell configurations, there is a maximum in the effective nuclear charge felt by the electrons (compared to the previous elements with no doubly-occupied orbitals) combined with relatively low interorbital repulsions due to the Pauli exclusion principle. "
I don't see how this answers any part of the question. Is it because I'm not understanding it or is it just a bad answer?
I also disagree with it. It contradicts my knowledge. When you compare one row of elements with half-filled subshell configurations with "previous elements with no double-occupied orbital" you're also referring to the further up the current row elements whose valence electrons have less shielding and therefore higher effective nuclear charge.
https://chemistry.stackexchange.com/questions/4766/melting-and-boiling-points-of-transition-elements
The specific question was:
The melting and boiling points of transition elements increase from scandium (1530 ∘C1530 ∘C) to vanadium (1917 ∘C1917 ∘C). They increase because as we go across the group, we have more unpaired (free) electrons. But at chromium (1890 ∘C1890 ∘C) however, the melting point decreases even though it has more unpaired electrons than the previous atoms. Why does this happen?
Part of the answer I'm confused about is "In half-filled subshell configurations, there is a maximum in the effective nuclear charge felt by the electrons (compared to the previous elements with no doubly-occupied orbitals) combined with relatively low interorbital repulsions due to the Pauli exclusion principle. "
I don't see how this answers any part of the question. Is it because I'm not understanding it or is it just a bad answer?
I also disagree with it. It contradicts my knowledge. When you compare one row of elements with half-filled subshell configurations with "previous elements with no double-occupied orbital" you're also referring to the further up the current row elements whose valence electrons have less shielding and therefore higher effective nuclear charge.