Middle School
Matter and Materials
Atoms, molecules, properties of substances, synthetic materials, and particle motion.
MS-PS1-1, MS-PS1-3, MS-PS1-4
2 lessons
4 quiz questions
Lesson 1: Atoms, Molecules, and Substances
Use particle models to explain matter and its properties.
Learning goals
- Describe matter as atoms and molecules.
- Use models to explain substances.
- Connect structure to properties.
Particles make up matter
Matter is made of atoms and molecules. Different substances have different particles or different arrangements of particles, which helps explain their properties.
Properties identify substances
Properties such as density, melting point, boiling point, solubility, conductivity, and magnetism can help identify and compare substances.
Lesson 2: Thermal Energy and State Changes
Explain state changes using particle motion.
Learning goals
- Describe particle motion in solids, liquids, and gases.
- Explain melting, freezing, evaporation, and condensation.
- Connect temperature to average particle motion.
Particle motion
Particles are always moving. In solids they vibrate in place, in liquids they move past one another, and in gases they move freely and spread apart.
State changes
Adding or removing thermal energy changes particle motion and spacing. During a state change, matter changes form but the particles themselves remain the same substance.