Outcome 2
Science Practical Skills (J42F 44)
Learners are required to perform four practical scientific procedures. The procedures must cover at least one practical from each of the areas of biology, chemistry and physics.
In doing so they must:
- (a) Complete the practical scientific procedures in accordance with given instructions.
- (b) Follow safe and hygienic practices throughout the practical scientific procedures.
For practical activities where individual skill and accuracy is important, then pair/group working is not appropriate. Examples of practical activities which should always be undertaken individually are:
The following are examples of practical activities where pair/group working could be appropriate:
- Assembly and use of gas collection apparatus
- Use of Boyle’s law apparatus
- Qualitative testing (eg carbohydrates)
For pair/group working the assessor must ensure that all learners are fully engaged and participating in the activity. In most cases group sizes larger than pairs would not be appropriate. However, it may be appropriate for learners to work individually or as pairs and then pool results with a larger group.
Assessors should complete a checklist for each learner which records accurately their performance in the task:
Target values and tolerances for the accuracy and consistency of the results should be set prior to the practical (but they should not be known to learners). The assessor should confirm that a learner has achieved these standards before progressing to outcome 3.
Examples of suitable experimental procedures are given below:
Biology
- The effect of pH or temperature on enzyme activity
- Investigating specificity of digestive enzymes
- Investigating osmosis in potato cylinders
- Counting yeast cells using a haemocytometer
- Preparation and staining of plant and animal cells
- The effect of light intensity on the rate of photosynthesis in pond weed
- The effect of exercise on pulse rate and breathing rate
- Investigating learning using a finger maze
Chemistry
- Testing effect of concentration, temperature or particle size on speed of reaction
- Measuring the pH of everyday substances
- Separation of colours in dyes by chromatography
- Constructing an electrochemical cell
- Testing of foodstuffs for starch and sugar
- Distillation of fractions from synthetic crude oil
- Formation and collection of product from a precipitation reaction
- Identification of salts by flame tests
Physics
- Measurement of average speed of a trolley/car on a slope
- Measurement of instantaneous speed of a trolley/car on a slope
- Measurement of acceleration of a trolley on a slope
- Comparison of the oscilloscope traces produced by AC and DC supplies
- Verification of Ohm’s law
- Verification of Boyle’s law
- Verification of Charles’ law
- Determination of speed of sound