Choosing Materials Based on Evidence

Compare, test, and group everyday materials based on hardness, transparency, magnetism, and flexibility.

Test, compare, and explain thermal and electrical conductivity in everyday materials.

Investigate how substances dissolve in liquids to form solutions and explore factors affecting dissolving rates.

Choose and use appropriate scientific techniques such as sieving, filtering, magnetic separation, and evaporation to separate mixtures.

Give reasons based on evidence from fair tests for why particular materials are chosen for specific products.

Demonstrate that changes of state, dissolving, and physical mixing are reversible changes.

Explain that irreversible changes produce new materials with new properties and identify examples such as burning, rusting, and acid reactions.