SME
General Chemistry I · Problem type
Ionization energy: rises or falls?
Use this for “Why is the first ionization energy of sulfur lower than that of phosphorus?”
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Going from the first element to the second, why does the energy change?
Tap a card, then tap its group.
Across a period the energy rises, except where the electron removed starts a p subshell or is the first to share a p orbital.
Assumptions
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First ionization energy is the energy to remove one electron, the easiest one, from a gaseous atom.
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Each card goes from the first element to the second; the brackets show the subshell the electron is removed from.
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Electrons in one subshell shield each other only a little, so each added proton holds them more tightly.
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