Ionic bonding occurs between a metal atom and a non-metal atom
For example sodium id the metal atom and chlorine is a non-metal
The metal atom always lose an electron and non-metal always gain
Sodium is in group 1 and has 11 electrons and 11 protons, this makes the atom neutral as electrons are negative and protons are positive and because there is the same amount the charge overall is 0.
The sodium atom looks like this:
All atoms need a full outer shell like the noble gasses to become stable atoms.
Sodium needs to lose the election in its outer shell to become stable. When it does this it becomes a positive ion. This is because electrons are negatively charged so when this electron is lost there is more protons than electrons which gives the atom an overall positive charge like so:
Chlorine is in group 7 and has 17 electrons and protons. The chlorine gains an electron and forms a negative ion. Which looks like:
So you can draw the reaction as a dot and cross diagram like this:
Lithium oxide is a more complex ionic bond as oxygen is in group 6 so needs to gain 2 electrons therefore 2 lithium atoms must react with the oxygen atom. Like so:
An Ionic lattice is a giant structure made up of loads of ions for example salt. One grain of salt is an ionic lattice. It is held together by a strong electrostatic force between oppositely charged ions. This causes it to have a high melting and boiling point as it takes a lot of energy to overcome the electrostatic force
It can only conduct electricity when molten as it doesn’t have any delocalised electrons so can’t carry charge but when molten the electrons are free to move.
Covalent bonding occurs between 2 non-metals. They share the electrons instead of transferring the electrons.
For example hydrogen is in group 1 so had one election. Hydrogen always exist as h2 as it covalently bonded and shares its electrons and looks like:
Another example is methane. The carbon atom is bonded with 4 hydrogen like so:
This gives it a tetrahedral structure. The hydrogen are bonded on a 109.5 degrees.