First Ionisation Energy Flashcards
Define the term first ionisation energy
energy required to convert a mole of isolated gaseous atoms into a mole of singly positively charged gaseous ions
Where is the decrease in ionisation energy between group 2 and 3?
magnesium and aluminium
Why is there a decrease in first ionisation energy between magnesium and aluminium?
magnesium: 1s2 / 2s2 / 2p6 / 3s2
magnesium lose from 3s orbital
aluminium: 1s2 / 2s2 / 2p6/ 3s2/ 3p1
aluminium loses form p orbital
p orbital of slightly higher energy, easier to remove
Where is the decrease in first ionisation energy between group 5 and 6?
phosphorous and sulfur
Why is there a decrease in first ionisation energy between phosphorous and sulfur?
phosphorous: 1s2 / 2s2 / 2p6 / 3s2 / 3p3
no paired electrons in p orbital (all single)
sulfur: 1s2 / 2s2 / 3s2 / 3p4
paired p orbital electrons repel
sulfur p electron easier to remove