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Are bonds formed in higher energy levels weaker?

  1. Mar 4, 2016 #1


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    If there was a bond in the 2p vs 3p subshell, which would be stronger? Taking into consideration that they are in the same group

  2. jcsd
  3. Mar 4, 2016 #2


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    Staff: Mentor

    There is no general rule that I am aware of. In some cases, you can only for molecules with excited atoms: excimer molecules.
  4. Mar 4, 2016 #3


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    I see, thanks. But then when you move down a group, doesn't the ionisation energy increase? Or am I mixing two different things?
    Last edited: Mar 4, 2016
  5. Mar 5, 2016 #4
    Quite the opposite really, moving down a group the general trend is 1st ionisation values tend to decrease; this is explained by the increase in the number of occupied energy levels causing an increase in atomic radius, therefore electrostatic attraction between valence electrons and the nucleus is weaker. Hence, 1st I.E values decrease moving down a group as the atom requires less energy to be ionised and overcome the electrostatic attraction.

    However, moving across a period 1st ionisation energy does increase as atom radius decreases; this is explained by the increase in effective nuclear charge (Zeff), therefore the valence electrons experience greater electrostatic attraction with the nucleus. Hence, 1st I.E values increase across a period as the atom requires greater energy to be ionised and overcome the electrostatic attraction.

    Thought I might write this to help elucidate your question, hope it helps.

    Yes, I suppose bonds made with electrons in higher energy levels are weaker as group three elements have expanded octets and thus can form more than the expected number of covalent bonds with other atoms. As a result, the electrostatic attraction could be weaker due to greater repulsion; this is probably explained by their smaller bond angles as electron domains form the greatest angles possible between one another to minimise repulsion. Hence, covalent compounds with trigonal bipyramidal and octahedral e- domain geometries tend to have smaller bond angles between electron domains compared to tetrahedral geometries, due to an increase in repulsion. This is just my guess.
    Last edited: Mar 5, 2016
  6. Mar 7, 2016 #5


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    I see thanks mate
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