In this activity, students observe and compare the features of a solution and a mixture.

What happens when we combine a liquid and a solid? When a solid dissolves, it seems to disappear. The dissolved solid is still there; we just can't see it.

Sugar is and example of a solid that breaks down into tiny pieces, and dissolves in water. When the sugar is spread completely throughout the water, we call this a solution.

Not everything dissolves, however. Rocks and sand do not dissolve in water—they sink to the bottom. We call this a mixture.

These activities are part of Science World’s Big Science For Little Hands program. They were developed and tested with preschool and kindergarten educators. Some of the activities are done in stations.

Mysterious Mixtures PDF from Big Science For Little Hands.

Objectives

• Observe and understand the process of dissolving.

• Compare the differences between a solution and a mixture.

Materials

• Per Student:
2 clear cups or other containers
a sugar cube
a rock (similar size as sugar cube)
water
spoon

Key Questions

• Pre-activity What will happen to the sugar when we add it to the water? What about the rock?
• Post-activity Where is the sugar now? Where is the rock now? Where did the sugar go? Can we get it back?

What To Do

1. Fill two clear cups or containers with warm water (which dissolves the sugar cubes faster than cold water).
2. Predict what will happen when you add the sugar cube and the rock to the water.
3. Add one sugar cube to one cup and a rock to the other cup.
4. Observe.
5. Taste the sugar water to see if you can detect the sugar (optional).

Extensions

• Experiment with other substances in your kitchen (e.g. drink crystals, hard candies, pepper, sand, flour, salt). What dissolves (makes a solution) and what does not (makes a mixture)?
• Compare how quickly a sugar cube dissolves when you stir it and when you let it sit still.
• Compare how quickly a sugar cube dissolves in cold water and in warm water.
• Dissolve and compare a white sugar cube and a brown sugar cube.
• Try pouring a small amount of sugar water into a shallow coloured dish. Allow the water to evaporate away (this might take a while). Can you find any sugar?
• Compare melting and dissolving. Melting is a change of state (from solid to liquid) while dissolving is a solid being integrated into a liquid.

Survivors

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Egg BB

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

Comet Crisp

Artist: Jeff Kulak

Jeff is a senior graphic designer at Science World. His illustration work has been published in the Walrus, The National Post, Reader’s Digest and Chickadee Magazine. He loves to make music, ride bikes, and spend time in the forest.

T-Rex and Baby

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Buddy the T-Rex

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Geodessy

Artist: Michelle Yong

Michelle is a designer with a focus on creating joyful digital experiences! She enjoys exploring the potential forms that an idea can express itself in and helping then take shape.

Science Buddies

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.

Western Dinosaur

Artist: Ty Dale

From Canada, Ty was born in Vancouver, British Columbia in 1993. From his chaotic workspace he draws in several different illustrative styles with thick outlines, bold colours and quirky-child like drawings. Ty distils the world around him into its basic geometry, prompting us to look at the mundane in a different way.