Chp 7

Cards (8)

define ionisation energy
How easily an atom loses electrons to form positive ions
what is 1st ionisation energy?
The energy required to remove 1 electron from each atom in 1 mole of gaseous atoms of an element to form 1 mole of gaseous 1+ ions.
Atomic radius
The greater the distance between the nucleus and the outer electron the lower the nuclear attraction
Nuclear Charge
the more protons in the nucleus, the greater the attraction between the nucleus and the outer electrons
What is electron shielding?
inner shell electrons repel outer shell electrons, this causes lower attraction between the nucleus and outer electrons
Describe the trend of 1st ionisation energy down a group
Atomic radius increases
more inner shells so shielding increases
nuclear attraction on outer electrons decrease
so, 1st ionisation energy decreases down the group
What is the general trend in 1st ionisation energy across a period?
Nuclear charge increases
similar shielding
nuclear attraction increases
atomic radius decreases
so, 1st ionisation energy increases as you go across a period
Define metallic bonding
the strong electrostatic attraction between the cations and delocalised electrons