Explain, using dot and cross diagrams, the formation of ionic compounds by electron transfer, limited to combinations of elements from groups 1, 2, 3 and 5, 6, 7
Dot and cross diagrams represent electron transfer. One atom will have dots as electrons, the other crosses.
For example: Sodium looses one electron, so is drawn on the right with one less. Chlorine gains the electron that sodium looses so is drawn with one extra electron: because the electron came from sodium it is a cross instead of a dot.
Understand ionic bonding as a strong electrostatic attraction between oppositely charged ions
Ionic bonding happens between two ions: they are attracted to each other due to their opposite charges, so we say the ions have electrostatic attraction. This attraction bonds them together into an ionic compound.
Understand that ionic compounds have high melting and boiling points because of strong electrostatic forces between oppositely charged ions
To melt or boil anything, heat is used to break bonds. The stronger the bonds, the more heat needed. Ionic compounds have strong bonds, so they don't melt or boil unless there is a considerable amount of heat, this means they have high melting and boiling points.
Describe the formation of a covalent bond by the sharing of a pair of electrons between two atoms
A covalent bond is a bond formed between atoms by sharing a pair of electrons (one from each atom).
Understand covalent bonding as a strong attraction between the bonding pair of electrons and the nuclei of the atoms involved in the…