Home Page


Monday 18th May

LC: To investigate dissolving


Three children have put some sugar cubes into a cup of tea.

They watch as the sugar cubes seem to disappear. What do you think has happened to them?

Read the thoughts below.

Who do you agree with?



The girl on the right is correct. 

Some substances dissolve when you mix them with water.

When a substance dissolves , it might look like it has disappeared, but in fact it has just mixed with the water to make a transparent (see-through) liquid called a solution.

Substances that dissolve in water are called soluble substances. 

When you mix sugar with water, the sugar dissolves to make a transparent solution.

Substances that do not dissolve in water are called insoluble substances.



You are going to test materials you have at home to investigate if they are soluble or insoluble.

You will need a cup/beaker of water and a teaspoon to stir.

Copy the table below in to your book. 

Have a go at testing a small amount of the materials below. 

Sand, salt, flour, sugar, coffee granules and salt. 


Remember to only test 1 material at a time.

Empty your cup/beaker and fill with new water when you are ready to test the next material. 


Task 2

Copy the question and record your prediction.


Next, copy the table below.

You will need a stopwatch to record the time the sugar takes to dissolve. Be careful when using hot water. Use a tea spoon to stir the sugar.


When you have completed your test, record your conclusion under the question below.


How does the temperature of the water affect the time time it takes the sugar to dissolve?