Activity 1 - What is the purpose of practical work?
In this activity delegates think about a range of practical activities using a selection of practicals taken from typical KS3 and KS4, or KS1 and KS2 schemes of work.
These are illustrated by brief instruction sheets (below). Each instruction sheet provides a weblink where full information can be found.
Working individually, each delegate attaches a label (e.g. a ‘Post-It’ note) to each practical to identify the key purpose or objective of the activity.
Working in small groups of three or four people, the labels are then classified under headings chosen by the group.
Note: If you are carrying out mixed primary-secondary CPD sessions you may find it helpful to print out the primary and secondary practicals on different colour paper.
List of secondarypracticals
1.Testing a leaf for starch
2.How much energy is there in food?
3.Preserving food
4.The causes of rusting
5.Melting and freezing stearic acid
6.Change in mass when magnesium burns
7.Law of reflection
8.Using ammeters
9.Experiments with magnets
10.Reaction between carbon dioxide and water
11.The Moon's distance from Earth
12.Chemicals from seawater
13.Looking at a heart
14.Effect of size on uptake by diffusion
15.Measuring reaction time of a human reflex action
16.Preparing a soluble salt by neutralisation
17.Alkali metals
18.Identifying the products of electrolysis
19.Ticker-timers for investigating speed
20.Simple electromagnet
21.Student power
22.Earthquakes in the laboratory
23.Water expands when it freezes
24.Extracting metals with charcoal
List of primary practicals
- Make friends with a tree
- Peace at last
- A light for
- Making Sandcastles
- Curtains
- Can colours compete with the sun
- Bone mystery
- Design a seed
- Paper towel magic
- Bishops can fly
- In control
- Colour mixing
- Look around you
- Slugs
- Investigating ice
- Kites
- Classroom percussion
- Magic or magnetic
- Moss mat
- Paper planes
Testing a leaf for starch
This procedure kills a leaf, disrupts the cell membranes and softens the cuticle and cell walls. This makes it possible to extract the chlorophyll with hot ethanol and also allows the iodine solution to penetrate the cells and react with any starch present.
How much energy is there in food?
Take samples of a range of foodstuffs and set them alight in turn. Burn food samples under a boiling tube containing a measured amount of water. Measure the temperature increase in the water. Calculate the amount of energy needed to cause that temperature increase. This gives an estimate of the amount of energy stored in the food. The apparatus is very simple and the protocol gives only a very approximate estimate for each foodstuff, so there is scope for students to suggest improvements in an evaluation.
Preserving food
Pupils investigate the effect of different preservatives on frozen peas in order to establish that decay is caused by the action of microbes, and therefore preservatives work by reducing microbe activity.
Law of reflection
Class experiment showing that angle of incidence is equal to angle of reflection.
Using ammeters
In this experiment pupils measure the current at various places in series and parallel circuits. This provides an opportunity to introduce the ampere unit.
Experiments with magnets
Magnets provide an introduction to attraction and repulsion, and to action at a distance. Pupils investigate pairs of magnets, plotting compasses and iron filings.
The Moon’s distance from Earth
An estimate of the ratio of the Moon’s distance from the Earth compared to its diameter. To complete this experiment, hold a small coin just beyond arm's length and adjust its distance from the eye until the disc of the coin just obscures the disc of the moon. A partner can then measure the distance from the eye to the coin.
Investigating the effect of caffeineon the reaction time of a human reflex action
Pupils use a familiar protocol (dropping and catching a metre ruler) to investigate the effect of drinking caffeinated drinks on their reaction times.
Ticker-timers for investigating speed
Making ticker-timer charts can develop an understanding of speed-time graphs.
One person should operate the ticker-timer switch while another walks away, pulling tape through the ticker-timer. The walker should speed up and then slow down and stop, while the tape is running through the timer.
Simple electromagnet
An introductory experiment using a wire wrapped round an iron nail, which shows that electromagnets can conveniently be switched on and off.
Student power
Students measure their personal power by running up a flight of stairs.
Water expands when it freezes
In this demonstration a bottle is filled with water and allowed to freeze. The water expands as it freezes which breaks the bottle. This is useful when teaching about the weathering of rocks and freeze-thaw.