Chapter 7: Periodicity Flashcards
General Trend across period
The s subshell fills first followed by the p subshell
General trend down the group
Same number of outer electrons so similar chemical properties
Ionisation energy?
The energy required to remove one mole of electrons from each atom of one mole of gaseous atoms
Atomic radius affecting ionisation energy
The greater the distance between the nucleus and the outer electron, the less the nuclear attraction
Nuclear charge affecting ionisation energy
The more protons there are in the nucleus of the atom the greater the attraction between the nucleus and the outer electron
Electron shielding affecting ionisation energy
The inner electrons repel the outer shell electrons so this reduced the attraction between the nucleus and the outer electron
Ionisation energy down the group
The ionisation energy decreases down the group
Despite Increased nuclear charge the outer electron is easier to remove due to increased shielding and larger atomic radius so the electron is less strongly attracted to the nucleus
Ionisation energy across periods
The ionisation energy increases across the period
The nuclear charge increases across the period attracting more electrons strongly. The atomic radius decreases because the number of protons increases. The shielding remains constant because the same shell is being filled.
Mtp of a metal
Melting points of metals are very high because of strong electrostatic attractions between the cations and delocalised electrons.
Mtp of giant covalent structures
Have a very high melting point because lots of strong covalent bonds which require lots of heat energy to break
Graphene
single layer of graphite hexagonally arranged carbon atoms
Thinnest and strongest metal ever made
Graphite
Composed of parallel layers of hexagonally arranged carbon atoms
Layers are bonded by weak London forces
Free delocalised electron to move
Periodicity
Is the repeating trends in physical and chemical properties shown by elements in periods on the periodic table
