Chemical Magic

Looking at the graph above, how much does the coin weigh?

Looking at the graph above, how much does the shiny coin weigh?

How much does the pile of dull, brown bits weigh?

When the sandpaper scratched the coin, it added new, shiny stuff onto the coin. The shiny stuff made the coin heavier.

• True
• False

The little brown bits were probably scratched off of the coin. That’s why the weight of the coin went down.

• True
• False

The sandpaper made the coin shiny, but nothing was added to it or scratched off of it. The dull, brown bits probably came from the sandpaper instead.

• True
• False

After 1 minute, the dull, brown bits are no longer visible. They aren’t in the tub at all any more. They’re totally gone! That’s why the total weight went down, and that’s why Maria couldn’t see them anymore.

• True
• False

After 1 minute, the dull, brown bits broke down into tinier and tinier pieces. Those tiny pieces were too small to see, but they were still in the tub. The weight went up because there were so many teeny tiny pieces.

• True
• False

After 1 minute, the dull, brown bits broke down into even smaller little bits. Those little bits were too small to see, but they were still in the tub. Those little bits all add up to the same amount of stuff as it was to start with, though. That’s why the total weight stayed the same.

• True
• False