: Understanding mass, volume, and density (
: Symbols of elements, atomic number (protons), and mass number (protons + neutrons). : Understanding mass, volume, and density ( :
Why is water not used to extinguish petrol fires? (Answer: Because petrol floats on water due to its lower density). : Understanding mass
Unit 1 typically focuses on the physical and chemical properties of matter and atomic structure. atomic number (protons)