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Exploring what happens when we put two different solid things together.
Imagine you have a jar of colorful marbles and a bucket of shiny sand. If you pour them together and shake them up, do the marbles turn into sand, or do they stay exactly the same?
A mixture is what happens when we put two or more different things together in the same place. Think about your toy box. Inside, you might have cars, blocks, and dolls. Because they are all in the box together, they form a mixture! In science, we look at solids—things that keep their shape—and see how they act when they touch. Whether you are mixing cereal in a bowl or pebbles in a driveway, you are making a mixture. The best part? You can have a mixture of just two things, or even twenty things! As long as they are together, it is a mixture.
Let's make a very simple mixture: 1. Take red blocks. 2. Take blue blocks. 3. Put them both into a plastic bucket and shake.
You now have a mixture of blocks!
Quick Check
If you put a pencil and an eraser in your pencil case, did you make a mixture?
Answer
Yes, because you put two different things together!
When we mix solid things like beads and sand, something very important happens: nothing changes about the items themselves! The sand is still tiny, grainy sand. The beads are still round, hard beads. They don't melt together, and they don't turn into a new 'sand-bead' material. In a solid mixture, every part keeps its own properties (how it looks and feels). If you look closely at a mixture of sand and beads, you can still see exactly which part is sand and which part is a bead.
Imagine you are at the beach: 1. You fill your bucket with cup of sand. 2. You find shiny seashells and drop them in. 3. You stir them with a shovel.
Even though they are mixed, the shells are still hard and the sand is still scratchy. They are just neighbors now!
Quick Check
If you mix green LEGOs and yellow LEGOs, do they turn into blue LEGOs?
Answer
No, they stay green and yellow because items in a solid mixture do not change.
Because the items in a solid mixture do not change, we can usually separate them. This means we can take them apart and put them back where they came from. If you have a mixture of big rocks and small sand, you could use your hands to pick out the rocks one by one. Or, you could use a tool like a sieve (a bowl with holes) to let the sand fall through while the rocks stay on top. Since the rocks didn't turn into sand, they are easy to find and move!
Let's try a harder separation: 1. Mix metal paperclips into a bowl of cups of rice. 2. To separate them, you could use your fingers, but that takes a long time. 3. Instead, use a magnet! The magnet pulls the metal paperclips out, leaving the rice behind.
The paperclips and rice are exactly the same as they were before they were mixed.
What is a mixture?
When you mix sand and beads, the sand turns into beads.
Which of these is a solid mixture?
Review Tomorrow
In 24 hours, try to remember the 'No Change' rule. What happens to a bead when you mix it with sand?
Practice Activity
Go on a 'Mixture Hunt' in your kitchen. Can you find a jar of mixed nuts or a bag of trail mix? See if you can identify the different parts!