Learning Lists for Science 4
Practical Work

Abstract

This page has a check list of tips for science practical work

Theory and Experiment
Stages of a Practical

Essentially science is a practical subject, and so lab and field work constitutes an important part of any science program. Do not skimp it, but use to to your own advantage, even if some of the student exercises seem tedious. At the very least be proud of accurate observation and recording of data.

A. Theory and Experiment

Science is both theoretical and practical
- Theory and practice are intimately linked
  - theory arises out of practice
  - theory points to new practices
- Experimental work, tackled with thought and a spirit of enquiry, will give you a deeper understanding of any scientific subject.
You might be tempted to treat practical work light-heartedly—Don’t:
- you must pass the practical examination
- otherwise you will fail fully to appreciate theory
- practical situations are increasingly a feature or the theoretical papers.
- if you have learned nothing from a practical period you have been just wasting your time!
Nevertheless your practical handouts will not always include detailed theory.
- Part of your scientific training is to refer to relevant sources of infonnation
- It is up to you to look up background information before an experiment and to seek explanations afterwards:
  - in textbooks
  - in references provided
  - in journals.

B. Stages of a Practical

Pre-laboratory—previous night:
- read the experimental handout/reference
  - make sure you understand the purpose of the experirnent
  - consider the experimental details:
    - note the possible hazards
    - analyse into separate steps
    - make a flow chart
    - know the reason for each step
    - do you need to select or devise any procedures in addition to those given?
    - check what data are required
    - do any preliminary or control experiments need to be done
    - what are the limitations and sources of error? how can they be minimised?
    - do any problems remain?—note them.
- prepare your lab notebook
  - fresh page—date title
  - write down the object of the experiment
  - draw the flow chart
  - make notes of details/problems
  - prepare tables for results.
In the laboratory:
- Before starting the experiment:
  - put on your lab-coat
  - ask the tutor about any difficulties
  - check that the apparatus/materials are available—if not, see the technician
  - check that no changes in procedtre have been made
  - assemble the apparatus—is it correctly functioning?
  - if in doubt—ask the tutor.
- During the experiment:
  - BE SAFETY CONSCIOUS
  - work individually for all qualitative/volurnetric analysis and observation experiments—if necessary work in pairs for more complicated preparations and physical chemistry experiments
  - take care when hand1ing:
    - materials—hazards and economy, don’t use too much
    - apparatus—often fragile—look after it
    - time—speed but not haste
  - make observations accurately—record them precisely
  - note any snags and how you overcome them
  - don’t change the procedure without informing the tutor—record all such changes
  - keep thinking!
  - Never act the fool, especially where there are dangerous chemicals or apparatus
- After the experiment:
  - clear your bench
  - make sure it is free from spillages, clean and dry
  - check the contents of your cupboard.
Post-laboratory:
- analyse the data
  - classify and/or tabulate results
  - plot graphs
  - do calculations
  - derive desired results—are they sensible?
- interpret the results and draw conclusions
- assess validity and reliability
- suggest improvements
- write up:
  - use your original notes—lab notebook
  - refer to further handouts on practical work.

You should develop a pride in doing precise work and recording it objectively. Always therefore record work as you do it in a notebook and be aware of possible sources of error, and possible hazards to yourself and to others.

-oOo-