Food colouring in water

Food colouring in water

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about drawing what you see in a science investigation
How to do this task 

  • Fill a jar 3⁄4 full of water.
  • Use a straw to add 1 drop of food colouring to the water.
a)
Watch the colour spread and draw what you see for each of these times.
 
  blank jar for drawing
Start		 blank jar for drawing
1 minute
   
blank jar for drawing
2 minutes		 blank jar for drawing
3 minutes
   
b) Describe what the colour looked like as it spread. The words in the box might help you.
 

water          drop          spread          mix         move          sink          float
 
 
 
 
 
 
 
 
 
Task administration: 
This task can be completed with pencil and paper.
 
Equipment:
Jar; food colouring; straw;  pencil same colour as food colouring; clock with second hand.
  • Cold tap water was used for classroom trials.
  • As an extension add 1 drop of food colouring to each of a jar of cold water and a jar of warm water (about 40°C) and then compare.
Level:
2
Curriculum info: 
Science, Investigating in science, Material World
Keywords: 
changes, diffusion, observation, investigation, drawing, practical
Description of task: 
This practical task requires students to make observations and draw diagrams about diffusion that occurs when food colouring is added to water.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Interpret representations
This resource provides opportunities to discuss what needs to be shown in a diagram to clearly show what was observed.
 
Science capabilities: 
Interpret representations
Answers/responses: 
a)

Diagrams completed for all 4 jars.
Diagrams show an increasing spread of the food colour.
b)

Any 2 of: 

  • The food colour spreads out.
  • The food colour sinks to the bottom.
  • The food colour sinks in long strings.
  • The food colour spreads out along the bottom of the jar.
  • The food colour goes around in circles. (This could happen if there is water movement).
  • Other acceptable answers.