A mixture is two or more substances mixed together, and we can pull them apart by how their parts differ in size or property.
Sand is caught by filter paper, iron bits are lifted out with a magnet, and salt water is evaporated to leave the salt.
The key is to notice which property differs first, then pick the matching method.
Tap each button and the three methods, filtering, evaporating, and the magnet, come into view one by one.
How do we separate mixtures?
To pull a mix apart again, you first have to ask which property is actually different. A pair that differs in grain size, a pair that looks like one body because something dissolved, and a pair that includes a side a magnet will hold do not split with the same tool. If you memorize method names first, you press filter paper onto every mix, and the dissolved side walks straight through the paper. Pick the difference first and the hand then goes toward filtering, evaporating, or a magnet.
Picking one of the three buttons swaps the whole picture. Filtering shows sand grains left in the upper funnel and water drawn in the beaker under the filter paper; the droplet shapes sit in place and do not fall. Evaporating shows a flame under a dish, salt squares left inside the dish, and bent lines above that mark vapor; those lines do not rise. The magnet pick shows a bar labeled N and S on top, gray grains near the bar, and brown grains left on the pile below.
🔬 Filtering
①Separates by size
②Example: sand + water → filter paper
③Use the difference in properties
④If one method fails, combine several
Why can we separate them?
It is easy to trust that filter paper alone can split every mix. Grains that have already gone into the water pass through the holes, so there is nothing left to catch. If you look only at size and skip the sticking trait, the side that holds and the side that does not stay in one pile. If you only warm the dish and never look at what stays, you also miss why the little squares sit inside the dish in the evaporating picture. So before you grab a tool, sort whether the gap is size, a boiling difference, or sticking.
💡 Difference in Properties
①Different size → filter (sieve, filter paper)
②Different boiling points → evaporate, boil
③Magnetic vs not → magnet
④Settling uses weight. It is not one of this page's three buttons; compare it in Grade 5 mixture separation
⑤Each substance has its own unique property
Summary
Separation Principle
Property difference → choose the method
Use differences in size, melting/boiling, magnetism, etc.
How can you pick out the sand from a mixture of sand and water?
1
Sand grains are large and water is made of tiny particles, so their sizes differ.
2
Filtering with filter paper lets the water pass while the sand is caught on the paper.
▸ Filter it with filter paper (using the size difference)
When particle sizes differ, separate by filtering.
Example 2
Iron filings and salt are mixed together. What tool would you use to pick out only the iron filings?
1
Iron filings stick to a magnet, but salt does not (difference in magnetism).
2
Holding a magnet near it makes only the iron filings stick and separate out.
▸ A magnet (using the difference in magnetism)
The difference in being attracted to a magnet separates the iron filings.
Unit-test style
Which statement about separating mixtures is correct?
①Filtering uses the difference in boiling point
②A magnet separates materials like iron that stick to it
③Salt in salt water is caught by filter paper
④A mixture can be separated by only one method
⑤Evaporation uses the difference in particle size
▸ ② A magnet separates materials like iron that stick to it
1
Iron is attracted to a magnet, so a magnet can separate materials like iron.
2
Filtering uses size (①), evaporation uses boiling point (⑤), salt dissolves in water and is not caught by filter paper (③), and a mixture can be separated using several methods together (④).