Atoms, Molecules & States of Matter
Aligned to MS-PS1 — Next Generation Science Standards.
What this lesson teaches
All matter is built from atoms that join into molecules. How fast those particles move and how tightly they're packed determines whether matter is a solid, liquid, or gas.
Worked example
In ice, water molecules vibrate in fixed positions (solid). Add heat and they move faster and slide past each other (liquid); add more and they fly apart (gas).
Practice questions
- Describe particle motion in a solid vs. a gas.
- What happens to particles when you heat a substance?
- Why does a gas fill its whole container?
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Átomos, moléculas y estados de la materia
Toda la materia está formada por átomos que se unen para formar moléculas. La rapidez con que se mueven esas partículas y qué tan juntas están determina si la materia es sólida, líquida o gaseosa.
Ejemplo: En el hielo, las moléculas de agua vibran en posiciones fijas (sólido). Al añadir calor, se mueven más rápido y se deslizan unas sobre otras (líquido); al añadir más calor, se separan completamente (gas).
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