CHAPTER NO 2 ionization energy
1. The first IONIZATION energy is the minimum energy required to convert one mole of gaseous
atom into one mole of unipositive ion by the loss of one mole of electrons.
2. The SUCCESSIVE ionization energy is the minimum energy required to convert one mole
of gaseous unipositive ion to one mole of gaseous di positive ion by the loss of one mole
of electrons.
FACTORS AFFECTING IONIZATION ENERGY
• Factor no 1 is the atomic radius, if the atomic radius is increasing the ionization energy is
decreasing as the distance between the nucleus and the valence electron increases so less
attraction is being experienced by the valence electron as weak attractive forces are present.
• Factor no 2 is the nuclear charge that is directly related to the ionization energy as if we see the
example of lithium there are 3 e- and 3 p+ but in sodium there are 11e- and 11+p so more
nuclear charge on sodium. Nuclear charge is referred to as the increase in attraction between
the e- and the p+.
• Factor no 3 is the shielding effect (it is the decrease in the attraction between the nucleus and
the valence e- caused by the inner shell electrons. If the shielding effect increases so the
ionization energy decreases as the inner electrons will stop the attractive forces to the valence
electrons.
2.TREND IN THE IONIZTION ENERGY:
• As we go down the group the atomic radius increases as the no of electrons increases so more
shells thus the distance increases between the nucleus and the valence electron, moreover,
the shielding effect increases as the no of inner electrons increases so they decreases the
attraction to the valence electron but
REMEMBER!!!!SHEILDING effect and the atomic radius
will have a dominant effect over the nuclear charge so as
we go down the group so the ionization energy decreases.
1. The first IONIZATION energy is the minimum energy required to convert one mole of gaseous
atom into one mole of unipositive ion by the loss of one mole of electrons.
2. The SUCCESSIVE ionization energy is the minimum energy required to convert one mole
of gaseous unipositive ion to one mole of gaseous di positive ion by the loss of one mole
of electrons.
FACTORS AFFECTING IONIZATION ENERGY
• Factor no 1 is the atomic radius, if the atomic radius is increasing the ionization energy is
decreasing as the distance between the nucleus and the valence electron increases so less
attraction is being experienced by the valence electron as weak attractive forces are present.
• Factor no 2 is the nuclear charge that is directly related to the ionization energy as if we see the
example of lithium there are 3 e- and 3 p+ but in sodium there are 11e- and 11+p so more
nuclear charge on sodium. Nuclear charge is referred to as the increase in attraction between
the e- and the p+.
• Factor no 3 is the shielding effect (it is the decrease in the attraction between the nucleus and
the valence e- caused by the inner shell electrons. If the shielding effect increases so the
ionization energy decreases as the inner electrons will stop the attractive forces to the valence
electrons.
2.TREND IN THE IONIZTION ENERGY:
• As we go down the group the atomic radius increases as the no of electrons increases so more
shells thus the distance increases between the nucleus and the valence electron, moreover,
the shielding effect increases as the no of inner electrons increases so they decreases the
attraction to the valence electron but
REMEMBER!!!!SHEILDING effect and the atomic radius
will have a dominant effect over the nuclear charge so as
we go down the group so the ionization energy decreases.
