This word list series is a free companion to our themed sets for grades 2–5. Each list gathers the key vocabulary from a topic and pairs it with fun facts or short notes that help the words stick. The aim is to give students a simple, engaging reference that connects directly to the theme they’re exploring. Physical Science Word List Forces and Motion Gravity, Friction, Push, Pull, Motion, Speed, Acceleration, Inertia, Force, Mass Matter and Materials Solid, Liquid, Gas, Atom, Molecule, Density