6th grade · Science · Unit 2 of 10
Mixtures & Solutions
Mix it, dissolve it, separate it
What your child practices
Telling pure substances from mixtures, mechanical mixtures from solutions, solutes and solvents, comparing concentration, and choosing separation methods like filtering, evaporation, magnets and distillation.
New York State Learning Standards learning standard: MS-PS1-8; MS-PS1-2 · mixtures as combinations of substances, and properties such as solubility that tell substances apart
How we explain it
Children can open this short lesson before they practice.
- A pure substance is one kind of matter, like gold or table salt. A mixture has two or more, like salt water or air.
- In a solution, one thing dissolves into another, like sugar in water.
- Separate mixtures by sifting, filtering, magnets or letting water evaporate.
- Sugar dissolves faster in warmer water.
Example: How could you get iron filings out of sand? Magnets pull iron, but not sand. Move a magnet through the mixture. Answer: use a magnet
Mixtures & Solutions in New York
In the New York State Learning Standards, this is unit 2 of 10 in 6th grade Science, after Body Systems and before Our Senses.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A solution that can't dissolve any more solute is called…
- pure
- evaporated
- diluted
- saturated
saturated
Hint: Keep adding sugar to water and eventually it piles up on the bottom. The solution is full, or saturated.
Question 2
What is a mixture?
- a single substance made of one kind of particle
- two or more substances combined, each keeping its own properties
- a substance that can never be separated
- a brand-new substance made by burning
two or more substances combined, each keeping its own properties
Hint: In a mixture, the substances are just mixed together. They can be separated again.
Question 3
Which change makes sugar dissolve faster?
🥄- using colder water
- putting a lid on the cup
- using bigger sugar lumps
- stirring the water
stirring the water
Hint: Stirring, warmer water and smaller pieces all help a solute dissolve faster.
Question 4
In fizzy water (carbon dioxide gas dissolved in water), which is a solute?
🧪- fizzy water
- water
- carbon dioxide gas
carbon dioxide gas
Hint: The solute is what dissolves (usually the smaller amount). The solvent does the dissolving (usually the larger amount). Together they make the solution.
Question 5
Mechanical mixture or solution? Tap an item, then tap its basket.
Sort into: 🥣 mechanical mixture · 🧪 solution
- 🏖️sand stirred into water
- 🍕pizza
- 🌬️air
- 🧂salt dissolved in water
- 🍵sugar dissolved in tea
- 🍪chocolate chip cookie
🥣 mechanical mixture: sand stirred into water, pizza, chocolate chip cookie · 🧪 solution: air, salt dissolved in water, sugar dissolved in tea
Hint: In a mechanical mixture you can see the different parts. In a solution, one substance dissolves into another, so it looks the same all the way through.
Question 6
Panning for gold works because gold is…
🪙- lighter than sand, so it floats
- dissolved in the river water
- denser than sand, so it sinks to the bottom of the pan
- magnetic, so it sticks to the pan
denser than sand, so it sinks to the bottom of the pan
Hint: Swirling the pan washes the lighter sand away while the heavy gold settles.