Skip to content
Pure Substances and Mixtures · Term 3

Physical and Chemical Properties of Matter

Differentiating between physical properties (e.g., density, melting point) and chemical properties (e.g., flammability, reactivity).

Key Questions

  1. Differentiate between a physical property and a chemical property with examples.
  2. Analyze how observing physical properties can help identify an unknown substance.
  3. Predict how a substance's chemical properties might influence its safe handling.

Ontario Curriculum Expectations

MS-PS1-2
Grade: Grade 7
Subject: Science
Unit: Pure Substances and Mixtures
Period: Term 3

About This Topic

Separation technologies involve using the physical properties of substances to pull mixtures apart. In this topic, students learn about methods such as filtration, evaporation, distillation, and magnetism. The Ontario curriculum emphasizes the practical application of these techniques in everyday life, such as water treatment, recycling, and the production of maple syrup.

Students also consider the environmental implications of these technologies, such as how we clean up oil spills or remove microplastics from our oceans. This topic connects science to engineering and social responsibility. Students grasp this concept faster through structured discussion and peer explanation of which separation method is best for a specific 'mystery mixture.'

Active Learning Ideas

Watch Out for These Misconceptions

Common MisconceptionFiltration can remove everything from water, including dissolved salt.

What to Teach Instead

Filters only catch particles larger than the holes in the filter. Hands-on testing of filtered salt water helps students see that dissolved substances require different methods, like evaporation, to be removed.

Common MisconceptionSeparation is only done in labs.

What to Teach Instead

We use separation daily, from brewing coffee to sorting laundry. Asking students to find 'separation technologies' in their own kitchens helps bridge the gap between school science and real life.

Ready to teach this topic?

Generate a complete, classroom-ready active learning mission in seconds.

Frequently Asked Questions

What are the most common methods of separating mixtures?
Common methods include filtration (for solids and liquids), evaporation (to recover a dissolved solid), distillation (to separate liquids with different boiling points), and magnetism (for magnetic materials). The choice of method depends on the physical properties of the substances in the mixture.
How does a water treatment plant use separation technologies?
Water treatment plants use several stages: screening to remove large debris, settling (sedimentation) to let heavy particles sink, and filtration through sand or charcoal to remove smaller impurities. They may also use chemical processes to clump tiny particles together so they are easier to filter out.
Why is it important to separate waste and recycling?
Separating waste allows us to recover valuable materials like aluminum, glass, and paper, which can be reused. This reduces the need for raw material extraction and decreases the amount of trash sent to landfills. Many modern recycling facilities use advanced separation technologies like optical sensors and magnets to sort items automatically.
How can active learning help students understand separation?
Active learning, particularly through 'design challenges,' forces students to think critically about physical properties. When a student has to decide whether to use a magnet first or a filter first to clean a mixture, they are applying their knowledge in a logical sequence. This problem-solving approach makes the science of separation much more engaging and relevant than just reading about it.

Browse curriculum by country

AmericasUSCAMXCLCOBR
Asia & PacificINSGAU