MrBadmusAI

Year 8 · Autumn First Half

Chemistry

4 lessons from 1 unit.

Unit C4 · lessons 1 to 4 of 5

Chemical reactions

Some changes make something new and some only move what was already there. This unit is about telling which is which, seeing what a reaction does to the atoms underneath, and learning the two ways chemists write one down.

  1. 01Chemical change vs physical changeContrastTwo changes can look identical — the same heat, the same colour change, the same disappearing solid — and only one of them makes something new. Which question separates them every time?Open this lesson
  2. 02Reactions rearrange atomsModelA new substance appears where two old ones were. Nothing was added and nothing left — so what actually happened?Open this lesson
  3. 03Word equationsModelYou can describe a reaction in a paragraph and still not have said what reacted. What has to be in the sentence for it to count?Open this lesson
  4. 04Mass in a reactionQuantitativeOne reaction on a balance loses two grams and another gains one and a half. Both obey the same rule — so what is the balance actually telling you?Open this lesson

Back to all three sciences this half term The whole KS3 Chemistry course