Question

How can the mass of a coin be decreased?

By melting the coin.
By breaking the coin into smaller pieces.
By compressing the coin with a vise.
None of the above will decrease the mass of a coin.

Answer 1

@aaronq

Answer 2

the mass of the coin is based on the number of atoms that make up the coin.

are any of these processes changing the number of atoms of the coin?

Answer 3

yes one if them

Answer 4

@aaronq

Answer 5

which one?

Answer 6

umm A

Answer 7

how?

a kg of water has the same number of atoms as a kg of ice, so that's not right.

Answer 8

C

Answer 9

@aaronq

Answer 10

how?

i feel like you're just guessing

Answer 11

i know it its d @aaronq

Answer 12

how do you know that?

Answer 13

Well First Of All You Can Not Break A Coin

Answer 14

of course you can break a coin, not with your bare hands though..

Answer 15

melting a coin can not decrease the mass of it its just breaking down particles

Answer 16

you're not breaking down particles when you melt it.

a coin when it's solid or liquid, it's still the same type of number and type of atoms.

these are physical changes, just like when you freeze and thaw water, it's still water

Answer 17

but youre right that it doesnt decrease the number of particles

Answer 18

ohh well now i knw so thanks for that now i can put it in my notes :)

Answer 19

good stuff!

Answer 20

So Is It D?

Answer 21

@aaronq

Answer 22

yes. the changes to the coin in options A to C are physical - the mass of the coin did not decrease. (even if they were chemical, the mass would not decrease because matter cannot be made nor destroyed, they just happened to be all physical changes).