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1.6 Ionisation Energies. First Ionisation Energy. LO: I understand what the first ionisation is. The first ionisation energy of an element is the energy required to remove one electron from every atom in one mole of free atoms. 1st ionisation energy of magnesium:. Mg(g). Mg + (g). +. e.
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1.6 Ionisation Energies First Ionisation Energy LO: I understand what the first ionisation is.
The first ionisation energy of an element is the energy required to remove one electron from every atom in one mole of free atoms. 1st ionisation energy of magnesium: Mg(g) Mg+(g) + e It is measured in kJ mol-1 1st ionisation energy of fluorine: F(g) F+(g) + e
LO: I understand how 1st ionisation energy changes throughout the Periodic Table. Ionisation Energy and the Periodic Table
Ne Ionisation Energy (kJ mol-1) F N O C Be B Li Elements of the 2nd period Across a period: In general, the 1st ionisation energy increases across a period from left to right. The increasing nuclear charge holds the outer electrons more tightly. More energy is needed to remove one outer electron.
Li Na Ionisation Energy (kJ mol-1) K Rb Cs Group 1 element Down a group: The 1st ionisation energy decreases down a group. There are two factors that decrease the 1st ionisation energy: • The distance between the nucleus and outer electrons increases. • The shielding effect of the inner electrons.
LO: I know what the 2nd ionisation energy is. Second Ionisation Energy
The 2nd ionisation energy is the energy needed to remove a second electron from every atom in one mole of free atoms once a 1st electron has already been removed. 2nd ionisation energy of magnesium: Mg+(g) Mg2+(g) + e 2nd ionisation energy of fluorine: F+(g) F2+(g) + e