Increases across a period as there are more
electrons being added to the outer shells.
The nuclear charge of a group is the same
because in a group they all have the same
number of electrons on their outer shells.
Atomic Radius
Increases down a group because more
shells are being added to the atom
making the radius bigger.
Decreases across a
period because the
electron attraction is
increasing, pulling the
electrons closer
together.
Electron Shielding
Stays the same across a period as the
electrons are being put in the same
shell.
Increases down a group
as more shells are added.
Nuclear Attraction
Increases across a period because the
atomic radius gets smaller and the
nuclear charge increases.
Decreases down a group due to
the increased atomic radius, so
there is more shielding.
Ionisation Energy
Decreases down a group
because the atomic radius
increases therefore the electron
shielding increases so the nuclear
attraction decreases.
Increases across a period because
the atomic radius decreases
therefore the nuclear attraction is
increasing, this makes it harder to
remove an electron.
Melting and Boiling Points
Giant Metallic Lattice
High Boiling and Melting Point that increases
with charge (1+ to 3+)
Giant Covalent Lattice
High Boiling and Melting Point
Simple Molecular Structures
Low Boiling and Melting Point that increases
with the amount of molecules it attracts (e.g
Oxygen being diatomic (O2)).
Period 3 Example
Periodic Table
Arranged in order of the
number of protons
(atomic number)