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Science Launch G5 / Week 02 / Launch Lab
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Week 02 · Nothing Lost

Launch Lab

Launch Lab: The clay challenge
// Weight stays the same when matter changes
⏱ about 15 min

Launch Lab: The clay challenge

Rocket rolls a ball of modeling clay in his hands. "I bet a long snake weighs more than a ball," he says. "It is longer!"

Raven hands him a wire hanger and two paper cups. "Let's build a balance and find out," she says.

They hang the cups from the hanger with string. Rocket balances the ball against a pile of paper clips.

Nova adjusts her glow so they can read the cups clearly. "Before plus nothing added equals after," she says. "Test it."

  1. The total weight of matter is conserved when it changes form.
  2. Melting and dissolving do not change the total weight.
  3. If gas escapes from an open cup, the scale shows less, but the matter moved into the air.
  4. A closed container keeps everything in, so the weight stays the same.
◇ HANGER BALANCE
Tie two paper cups to the ends of a wire hanger with string.
Hang the hanger from a doorknob or a broom handle across two chairs.
Put a ball of clay in one cup. Add paper clips to the other cup until the hanger is level.
Take out the clay and roll it into a long snake. Put it back in its cup.
Check the balance. Did it stay level?
For a grown-up
Ask: what did you notice? What would you change?
Ask how many paper clips balanced the clay, and whether that number changed after reshaping.
WEEK CHECK
  • Read the question.
  • Tap your answer.
Rocket reshapes a clay ball into a snake. What happens to its weight?
Why did the open fizzing cup weigh less?
When matter changes form, the total weight is ____.
Baking soda and vinegar make a gas called carbon ____.
Water 100 grams plus sugar 5 grams. What does the sugar water weigh? Type the number of grams.
WHY THIS EXERCISEBefore plus before equals after.

You tested a big science rule three different ways this week. Next week we will become material detectives.

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