States of matter
There are some lovely demonstrations and investigations here which look at solids, liquids and gases.
Try This - Pouring a Gas
A striking demonstration that shows that gases, as well as liquids, can be poured. This article is pretty self explanatory but here are a few tips:
- Practise before you do this for the first time in front of a class to make sure you’ve got the amounts of bicarbonate and vinegar right.
- A dilute acid (eg 0.2M hydrochloric) works just as well as vinegar.
- Carbon dioxide is heavier than air so you won’t lose much from the jug even if you don’t keep your hand over it.
- You can extend the demo by trying to re-light the tea light – since the glass is still full of carbon dioxide it won’t light. However, if you remove the candle from the glass it will light easily
Antibubbles
This lesson links aspects of states of matter to the use of bubbles to deliver drugs to cancerous tissue, and is appropriate to students aged 12- 14. Most children will be familiar with soapy bubbles consisting of gas surrounded by a film of moisture. This lesson looks at the formation of bubbles that contain liquid surrounded by a ‘membrane’ of gas, giving rise to the name 'antibubbles’.
The purpose of the practical activity is to explore the behaviour of matter in a novel situation, and to encourage students to offer explanations for their observations.
Stuff and Substance: Ten Key Practicals in Chemistry *suitable for home teaching*
A really useful book from the Science Enhancement Programme about particles and activity A2 is particularly recommended to help teach this section of the Key Stage Three curriculum. The experiments and demonstrations are simple but the ideas behind them are fundamental for a good understanding of chemistry at any level.
A well designed sequence of activities prompts students to think deeply about what is going on when liquid water turns to steam. There are helpful and detailed teacher notes starting on page 16 of the booklet (page 16/65 if using the pdf file) although teachers may well find that they want to read through the earlier sections of the booklet too.
Both word and pdf versions of the student worksheets are available and teachers may also like to use some of the slides in the presentation (part 1) to help with explanations.
