Modeling Molecules & Structures
Aligned to MS-PS1-1 — Next Generation Science Standards.
What this lesson teaches
Every substance is built from atoms joined in fixed patterns. A molecule model shows which atoms and how many are bonded together, while an extended structure repeats that pattern across millions of atoms.
Worked example
A water molecule model shows two hydrogen atoms bonded to one oxygen atom (H2O). Table salt is an extended structure instead — sodium and chloride ions repeat in a 3D grid, so there is no single salt molecule, just a giant lattice.
Practice questions
- Observe a diagram of carbon dioxide and identify how many atoms of each element it contains.
- Build a model of methane (CH4) with beads or drawings and label every atom.
- Explain why a diamond is called an extended structure rather than a molecule.
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
Modelar Moléculas y Estructuras
Toda sustancia está formada por átomos unidos en patrones fijos. El modelo de una molécula muestra cuáles átomos y cuántos están enlazados, mientras que una estructura extendida repite ese patrón a lo largo de millones de átomos.
Ejemplo: El modelo de una molécula de agua muestra dos átomos de hidrógeno enlazados a un átomo de oxígeno (H2O). La sal de mesa es en cambio una estructura extendida — los iones de sodio y cloruro se repiten en una red tridimensional, así que no existe una sola molécula de sal, sino una red gigante.
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