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Changes Around Us: Physical and Chemical

Fold it, cut it, crumple it

Fold a sheet into a boat. Open it again. It is still paper.

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The idea

One flat sheet: 432 cm², 4 g.
Step 1 of 4
  1. One flat sheet: 432 cm², 4 g.
  2. Folded twice the same way: 4 layers.
  3. Cut straight across the stack.
  4. Opened out: 5 pieces. Still 432 cm², 4 g.

A physical change changes shape, size or form. No new substance is made.

The rule

To crumple is to squeeze paper into a ball.

Folding and cutting change the shape. The paper stays paper. No new substance is made.

One sheet, three things done to it
What you doWhat changesWhat stays the same
Fold itIts shapePaper, 432 cm², 4 g
Cut itHow many piecesPaper, 432 cm², 4 g
Crumple itIts surfacePaper, 432 cm², 4 g

Jump to lesson

This track

  1. 0 Start here
  2. 1 Fold it, cut it, crumple it
  3. 2 Ice, water and steam are one substance
  4. 3 Dissolving is not disappearing
  5. 4 Some of these will not go back
  6. 5 Checkpoint: changes that make nothing new
  7. 6 A test for something new
  8. 7 Five signs, and what each one is worth
  9. 8 One candle, two changes at once
  10. 9 Two questions, not one
  11. 10 Slow changes in rocks
  12. 11 Checkpoint: new substances and the two questions
  13. 12 Burning needs air
  14. 13 The fire triangle
  15. 14 A change written in words
  16. 15 Useful and harmful changes
  17. 16 Checkpoint: burning, equations and useful changes
  18. 17 The big picture
  19. 18 Track quiz

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