C8 The Periodic Table And Periodicity Flashcards
Periodicity
A repeating pattern, in either physical or chemical properties, across different periods
First ionisation energy
The energy required to remove one electron from the ground state of each atom in a mole of gaseous atoms of that element, to form a mole of gaseous ions of charge 1+
S block
Group 1 and 2
D block
Group 3 to 12
P block
Group 13 to 17
Trends across a period
Atomic radius decreases
Metallic- covalent
Giant lattice- simple molecular- simple atomic
Good (first 3)- Poor
Melting point increase to silicon, drop at Phosphorus, increase then decrease
Ionisation energy increases
Trends down group 2
Atomic radius- increases
Ionic radius- increases
Melting point- high, decrease, increase, decrease, increase
1st ionisation energy- decreases
Trends down Group 17
Atomic radius increases
Ionic radius increases
Melting point increases
1st Ionisation energy decreases
Atomic radius across a period
Radius decreases left to right
The charge of the nucleus increases
The shielding remains the same
Atomic radius down a group
Atomic radius increases
Charge of the nucleus increases
The shielding increases
Bonding and structure across a period
Metallic > covalent > /
Giant > simple molecular > simple atomic
Bonding and structure down a group
Non metallic / giant covalent lattice> metalloid > metallic/ giant metallic lattice
Electrical conductivity
Metals in group 1 and 2 are the best conductors and then metalloids
Graphite can conduct electricity due its sea of delocalised electrons
Factors for first ionisation energies
Also for down a group
Atomic radius = decrease
Nuclear charge = increase
Shielding effect = decrease
Ionisation energy across a period
Atomic radius= increase
Nuclear charge = increase
Shielding affect = increase
