1.30 recall the charges of common ions in this specification

K +
Na +
Li +
H +

Mg 2+
Ca 2+

Al 3+

Cl-
Br-
I-
F-
OH-

NO3-

SO4 2-

CO3 2-

1.36 describe an ionic crystal as a giant three-dimensional lattice structure held together by the attraction between oppositely charged ions

An ionic crystal is a lattice of electrons in a 3D structure, the ions are alternate positive and negative and their opposing charges hold the structure together.

1.37 draw a diagram to represent the positions of the ions in a crystal of sodium chloride.

In a lattice structure with negative touching positive and visa versa.

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1.35 understand the relationship between ionic charge and the melting point and boiling point of an ionic compound

The bigger the difference in charge, the stronger the attraction: if you have + and - ions they will have a weaker bond than +3 and -3 ions. The stronger the attraction, the harder it is to break the bonds, this means that the melting and boiling points will be higher. So the bigger the charge of an ion, the higher the melting and boiling point.

1.34 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 the have high melting and boiling points.

1.33 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.

1.32 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.

Here we begin with sodium and chlorine. 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.

The ions are drawn in brackets with their charge written outside.

Sorry the picture is hard to see.

1.31 deduce the charge of an ion from the electronic configuration of the atom from which the ion is formed

This is a way of working it out:

• How many electrons are on the outer shell?
• How many shells does it have?
• To fill up its outer shell how many electrons will it take?
• Now see weather it will take more transferring to loose electrons (to go down an shell,) or gain electrons (to fill the shell)
• Which ever one takes the least transferring will be the route that was taken
• If it lost, it will have a positive charge of the number of electrons lost to empty the shell
• If it gained, it will have a negative charge of the number of electrons it gained to fill the shell

Most of the time the atoms will be on the second orbital in which case its simpler to think of it like this:

An atom with less then four electrons on its outer shell will want to loose electrons because that is the quickest way for it to have a full outer shell: if all the current electrons on the outer shell go, then the next shell- which will be full- will become the outer one. So we know they will loose electrons to make positive ions. If you have a group 2 atom (2 electrons on outer shell) it will loose two electrons when it becomes an ion, so you know it will have a +2 charge.

Similarly atoms with more than four electrons will gain electrons to fill their outer shell. This means they will make negative ions: as an example a group 7 electron has to gain one electron to fill its outer shell and so will become -1.

1.29 understand oxidation as the loss of electrons and reduction as the gain of electrons

The name given to loosing electrons is oxidation; the name given to gaining electrons is reduction.

One way to remember this is oil rig:
Oxidation
Is
Loss
Reduction
Is
Gain

1.28 describe the formation of ions by the gain or loss of electrons

Electrons are transferred from one atom to another (this is in an effort to either fill or empty the outer shell to become stable.) An atom has no charge because the electrons and protons have equal and opposite charges. But an ion will have a charge: an electron has a charge of -1, so loosing an electron looses one negative charge, making the ion +1. So gaining one electron will make an atom a -1, gaining two will make it -2.

The atoms the gain or loose electrons to each other will have opposite charges: for example if a gives away 1 atom and b gains it, a is +1 and b is -1. These charges mean that the ions are attracted to each other (ionic bond), so they form an ionic compound.