Ionic bonding does not involve the sharing of electrons, that one is false. In ionic bonding, the metal's electrons are given to the non-metal, so that they're both like the nearest noble gas (full electron shells.) They are then drawn together because one has a negative charge (the non-metal) and one has a positive charge (the metal.)
Oxide ions have a 2+ charge: This is false, oxide ions have a 2- charge.
Electrons do have a negative charge, this is true.
Hydrogen molecule: pretty sure this is true. We know this because both atoms are non-metals.
The last one is true: a covalent bond is a shared pair of electrons between two atoms, however be aware that there can be more than one covalent bond between two molecules.
