# Triangular tips

14th January 2005 at 00:00
Physics is about how the world works, from the smallest subatomic particles to the ultimate fate of the universe. When revising, students need to be able to remember things such as the life cycle of a star, at the same time as performing calculations. This schism causes many difficulties.

Audit: just because students covered a topic 18 months ago doesn't mean they have total recall Use brief questions for formative assessment early in the revision process; the extension paper questions on the Testbase website is a good place to start. Be clear about the level your students are taking, as some topics are only higher tier. Think about the keywords examiners are looking for. Students tend to be handicapped by the inability to articulate ideas on paper. How can you overcome this?

Overlap: look for areas of commonality between subjects - atomic structure and earthquakes overlap with chemistry - or use cross-curricular contexts such as energy flow in food webs, or how the eye or ear works. This helps students understand the concepts. A new context or a different teacher can often make a concept click.

The right formula: formulae can be remembered using triangles and acronyms.

For example, Ohm's law becomes VIRus to accompany:

V = potential difference (in volts)

I = current (in amps)

R = resistance (in ohms)

Practise: calculations require practice. Demonstrate worked examples, then give five more to attempt and mark them immediately. Ensure students always show working for calculations and all answers have units. For longer descriptive questions use bullet points, unless there is a clear indication that the quality of English is assessed - this is normally indicated by a pencil in the margin.

Content hotspots: radioactivity. Students often confuse atomic number and atomic mass. Lego bricks (red for protons; blue for neutrons) can help.

Make several nuclei (eg carbon, iron, helium and, if you feel very brave, uranium) and ask students to identify the element from the periodic table.

Then try an alpha decay by removing two protons and neutrons. The bricks help students see what is in a nucleus. This conservation of particlesbricks is what aids understanding.

Electricity: potential difference and current are often muddled and there are many misconceptions. There are excellent ICT aids available. Link the voltage to the transfer of energy in a circuit. Try using a pop-up motor to explain why a motor turns.

Websites

Testbase: www.testbase.co.uk

General: www.bbc.co.ukbitesize Electricity: www.FurryElephant.com

Free periodic tables: www.GSK.com

Dr Steven Chapman is head of physics at Oxted School, Surrey

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