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Bonding and structure

Video clips and animations

Ionic bonding from the BBC

Good explanation (over 6 pages) of ionic bonding from the BBC.

Ionic bonding from the Fuse School

Another brief explanation, covering three ionic compounds. YouTube.

The structure of sodium chloride

Short animation of the structure of a sodium chloride crystal, showing how the coming together of the ions leads to the model of the crystal we normally use. YouTube.

What happens to sodium chloride when it dissolves in water

Shows how a salt crystal is pulled apart by attractions involving water molecules. The animation uses the terms anion (a negative ion) and cation (a positive ion). It also mentions attractions involving lone pairs on the oxygen atom in a water molecule. If you draw a dots-and-crosses diagram for a water molecule, you will notice that there are two pairs of shared electrons between the oxygen and the hydrogens, and two more pairs on the oxygen which aren't involved in bonding. These are the lone pairs. YouTube

A comparison of ionic and covalent bonds

Shows how molecules are formed by sharing electrons when one of the atoms doesn't have enough "pulling power" (the proper term is electronegativity) to pull an electron completely away from the other atom. One thing I don't like is that it says that the bonding in DNA is largely covalent. That is perfectly true, but ignores the importance of another type of bonding called hydrogen bonds which holds the two strands together. YouTube

Simple properties of covalent compounds

This is a useful introduction to intermolecular forces (the forces between separate molecules) and the way they affect melting and boiling points. It doesn't explain the origin of these forces, but you can explore that further if you want to in a link below. YouTube

Giant covalent structures in diamond and graphite

Simple explanations of the differences between diamond and graphite. One small niggle! The hexagons in each layer in graphite extend in two dimensions to give sheets of hexagons, not just a row of them. Presumably for reasons of clarity, this video doesn't show this, but it should at least have been mentioned. YouTube

Allotropes of carbon

Allotropes are different forms of the same element in the same physical state. This video looks again at carbon as diamond and graphite, but adds graphene and the fullerenes. YouTube

Metal bonding

Excellent discussion of metallic bonding. In case you haven't come across it before, the commentary frequently refers to valence electrons. Valence electrons are simply the electrons in the outer levels of atoms which can be involved in various types of bonding. YouTube

Other interesting sites

Intermolecular forces

An introduction to intermolecular forces from the main part of Chemguide. Aimed at A level, but accessible to GCSE students who might be interested.

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© Jim Clark 2017