Magnesium is a highly reactive metal which reacts violently with oxygen to produce a white solid called magnesium oxide.  This can be shown as follows:   Chemical equations are a useful shorthand way of describing the changes that take place when a chemical reaction happens.  Word equations can be helpful for example :...

 Crude oil is a mixture of alkanes ( hydrocarbons)

Use the animation to measure the bond angles in each of the three molecules below:

 a game to test your skills