Chemistry Basics
MS-PS1-2MS-PS1-5
Identify reactions and apply conservation of matter
Identify signs of chemical reactions.
Learn the skill
- 1Identify signs of chemical reactions.
- 2Use conservation of matter to reason about reactants and products.
Cited instruction
Use the publisher's material for instruction, then return to PeerTutor for the checked practice written for this skill.
Chemical reactions · Khan AcademyPractice preview
40 molecules each contain 4 atoms before a closed-system reaction. How many atoms must be represented after the reaction?
Reactants have total mass 410 g. Products should have what total mass in a closed system?
12 molecules each contain 5 atoms before a closed-system reaction. How many atoms must be represented after the reaction?
Course mapping reviewed by Nikhil on 2026-08-26. Practice is authored for PeerTutor and does not reproduce linked providers' exercises.