Naming Equipment

Investigative Terminology

Keyword DefinitionIndependent variable

The things that are being kept the same

Dependent variable If all your repeat readings are very close together

Control variables The variable that you are changing

Reproducible The idea that you are testingRepeatable The variable you are measuringHypothesis If other groups get the same

pattern or results as you

Risk Assessments• These are carried out to make sure that we all do

investigative work safely• You have to think about the things that could go

wrong, what injury they could cause and how you can prevent them.

• They are usually set out in a table:Hazard – what could cause

an injury?Risk – what injury could it

cause?Control – How could you

prevent the injury?

Glassware (beakers, test tubes etc.)

Cuts Don’t put glassware near the edge of the bench. Sweep up broken glass.

Chemical Burns to skin and eyes Wear goggles, tie hair back, wash off skin immediately

Bunsen Burners Burns Wear goggles, tie hair back.

Writing a Method

• A scientific method needs to contain several things:– An equipment list (including size of glassware and

strengths of chemicals)– A diagram showing how to set up the experiment– A step-by-step how to do the experiment (a bit like a

recipe)– What you are going to measure, change and keep the

same– How you are going to keep your control variables the

same– A risk assessment

Writing a Method

• Have a go at writing a method for this practical:– You are going to time how long it takes for 1cm

pieces of magnesium to dissolve in 1.0Mol/dm3 hydrochloric acid.