Separating Mixtures Separating Mixtures
Mixtures are substances mixed together, and each keeps its own properties, so we can split them.
We filter sand by size, recover salt by evaporating water, and lift iron filings with a magnet.
Those property differences are the key.
Press the filter, evaporation, and magnet buttons to see each one work.
How Do We Separate Mixtures?
Filter Paper Evaporation Magnet
see gongsik.com
Mixture separation methods — filter, evaporation, magnet 🔬 Principles of Each Method
①Filter paper: uses particle-size difference
②Water passes the paper but sand is trapped
③Used for sand+water mixtures
④Great for separating solids and liquids of different sizes
Separation Methods by Mixture Type
Method Comparison
Chart Mixture Separation Methods Compared
Method Property Used Example Mixture Type Filter Paper Particle size Sand + water Solid + liquid Evaporation Boiling point Salt + water Dissolved solid + liquid Magnet Magnetism Iron + sand Solid + solid Sedimentation Weight (density) Soil + water Solid + liquid
💡 How to Choose a Method
①First identify the mixture type
②Solid + liquid → filter or settle
③Dissolved solid → evaporation
④Magnetic substance mixed in → magnet
⑤Differences in properties are the key!
Summary
Principle of Mixture Separation
Property difference → choose a suitable method
Use differences in size, boiling point, magnetism, weight, etc.
Main Methods
Filter (size) / Evaporation (BP) / Magnet (magnetism)
First understand which property differs
🎯 Key Points
①Mixture: two or more substances mixed
②Filter paper: separates by size (solid–liquid)
③Evaporation: separates dissolved solids by boiling point
④Magnet: separates by magnetism (solid–solid)
⑤Use property differences to split mixtures
Examples and Unit Test
Example 1
How can you obtain salt from salt water?
1 The salt is dissolved in the water, so filter paper cannot catch it.
2 Heating the salt water turns the water into vapor, leaving only the salt (evaporation).
▸ Evaporation (boiling off the water leaves the salt behind)
A dissolved solid is separated by evaporation.
Example 2
How do you separate a mixture of iron filings and sand?
1 Iron filings stick to a magnet, but sand does not (difference in magnetism).
2 Bringing a magnet close attracts only the iron filings, separating them.
▸ Magnetic separation (only iron filings stick to the magnet)
Using the difference in magnetism, you can split iron filings from sand.
Unit-test style
Which statement about separating mixtures is correct?
① Salt in salt water can be caught with filter paper
② Iron filings and sand can be separated with a magnet
③ Evaporation uses the difference in particle size
④ Filter paper catches dissolved salt
⑤ Mixtures cannot be separated
▸ ② Iron filings and sand can be separated with a magnet
1 Iron filings stick to a magnet while sand does not, so a magnet separates them.
2 Dissolved salt passes through filter paper (① and ④), evaporation uses boiling point (③), and mixtures can be split by property differences (⑤).