Scientific method

Science aims to develop a good explanation of natural events (phenomena) that are observed.

Scientists develop explanations using the scientific method. This follows a specific way of working:

  • propose a hypothesis, an initial theory or explanation for an observation
  • make a prediction based on the hypothesis, suggesting how changing one factor will affect the outcome
  • Plan an experiment - this should test the prediction and the hypothesis on which it is based

Planning experiments

It is important to choose appropriate apparatus, materials and techniques.

Apparatus needed for titration: burette, pipette, conical flask and pipette filler.An example of equipment that could be used in an experiment


Containers including:

  • test tubes
  • boiling tubes
  • beakers
  • flasks

Measuring apparatus including:

Heating and electrical apparatus including:

  • Bunsen burners
  • electric heating mantle
  • water bath
  • power pack
  • leads, crocodile clips and electrodes


Reacting chemicals including:

Chemicals for analysis including:


Standard techniques of measurement. The table gives some examples

pH meterpH
Digital balanceMass
Measuring cylinderVolume of liquid
BuretteVolume of liquid in titration
Gas syringeVolume of gas

Methods of analysis including

  • chromatography
  • flame tests to identify metal ions
  • chemical tests to identify gases or ions
  • titration

Methods for carrying out reactions including:

  • test tube reactions
  • heating methods, such as Bunsen burner, electric heating mantle, water bath
  • electrolysis