ChemistryWhen You Mix Things You Might See the Parts or Something New
Atlas stands at a big wooden table covered with jars of colored sand, cups of water, and bowls of rice and beans, carefully pouring two things together and peering at the result with wide, curious eyes.
- Identify when a mixture shows its separate parts, like sand and pebbles mixed together.
- Identify when a mixture looks like something new, like salt stirred into water.
- Compare two mixtures and describe what you can still see in each one.
- Predict whether mixing two materials will show the parts or look like something new.
Key terms
- mixture
- two or more things put together that you can sometimes still see
- dissolve
- when a solid spreads through water in pieces too tiny to see
- separate parts
- the different pieces in a mix that you can still see and pick out
- looks new
- when a mix changes so much you cannot see the original parts anymore
Mixes Where You See the Parts
Sometimes when you mix two things, you can still see both parts clearly. If you stir red beans into white rice, the beans stay red and the rice stays white, and you could pick them apart again. The same is true for gravel mixed with sand or buttons mixed with paper clips. In these mixtures, each thing keeps its own color and shape, so you can always spot the separate parts.
Mixes That Look New
Other times, mixing two things makes the mixture look like something brand new. When salt dissolves into water, the salt spreads out so much that you cannot see it anymore, though the water now tastes salty. When you mix blue paint and yellow paint, you get green, and the blue and yellow seem to vanish. These mixtures look new because the parts spread out or blend so well that your eyes cannot tell them apart.
Looking Closely
The way to tell these two kinds of mixes apart is to look closely at what you can see. Ask yourself whether you can still spot each part, like beans in rice, or whether the mix looks like one new thing, like green paint or salty water. Even when a mixture looks brand new, the parts are usually still there. The salt is hiding in the water, just spread out into tiny invisible pieces.
Worked examples
Decide if gravel mixed with sand shows its parts.
- Picture pouring gravel and sand together in a bowl.
- Gravel stays as bigger chunks and sand stays as tiny grains.
- You can still see and pick apart the gravel and the sand.
Answer: Yes, it shows its parts because you can still see the gravel and the sand separately.
Activity
Sort each mixture — can you still see the parts, or does it look like something new?
Practice
Predict whether sugar stirred into water will show its parts.
Name two mixtures where you can still see both parts.
Common mistakes to avoid
- Salt is destroyed when it mixes into water.The salt is not gone; it spreads through the water so you cannot see it, but the water tastes salty.
- Every mixture lets you see both parts.Some mixtures look brand new, like green paint, because the parts blend so well you cannot see them.
Check your understanding
You mix pebbles and sand in a bowl. What do you see?
Atlas stirs sugar into warm water and the sugar seems to vanish. What happened?
Which mixture lets you still see BOTH parts you put in?
Recap
When you mix things, sometimes you can still see the separate parts, like beans in rice, and sometimes the mix looks brand new, like salt in water or green paint. Looking closely helps you tell which kind of mixture you have.
Reflect
What is a mixture you have made that looked brand new?