Atoms, Molecules, and Compounds Basics
The Building Blocks of Matter Grade 9 Science 60-minute lesson
What is matter made of?
Think about the water you drink The air you breathe The desk you're sitting at What do they all have in common?
Atoms: The Smallest Units
Atoms are the smallest units of matter Cannot be broken down by chemical means Made up of protons, neutrons, and electrons Like the letters of the alphabet
Molecules: Atoms Joined Together
Two or more atoms bonded together Can be the same element (O₂, H₂) Can be different elements (H₂O, CO₂) Like words made from letters
Compounds: Different Elements Combined
Molecules made of different types of atoms Properties different from original elements Examples: water (H₂O), salt (NaCl) Like meaningful sentences
Comparing the Building Blocks
{"left":"ATOMS: Single units, Cannot be broken down chemically, Made of protons, neutrons, electrons\nMOLECULES: Two or more atoms bonded, Same or different elements, Can be broken down into atoms","right":"COMPOUNDS: Molecules with different elements, New properties formed, Examples: H₂O, NaCl, CO₂"}
Classification Challenge
Work in groups of 3 Sort the model cards into categories: • Atoms • Molecules • Compounds Justify your choices with evidence!
Key Takeaway
"Everything around us is made of atoms that combine in different ways to create the amazing diversity of matter in our universe."