Is this a CHEMICAL change or a PHYSICAL change!?

Question:help so if its a chemical change it has clues : transfer of energy, change in color, production of gas, formation of a precipitate... but im way too dumb to know this stuff! ugh

1.) A copper wire is bent
2.) Charcoal burns in a grill
3.) Bread dough rises when yeast is added
4.) Sugar dissolves in water

and if its chemical change whats the clue?
im soo dumb k thanks

Answers:
Well, if a copper wire is bent, its still made up of the same chemicals... so that would be a physical change.

When Charcoal burns, I would assume that it goes through both a chemical and physical chance...

The third one... look at "When yeast is added." The added yeast makes a chemical change.

When sugar disolves in water, the sugar is still there, it just physically changes.

Hope this helps.
1.) A copper wire is bent-physical
2.) Charcoal burns in a grill-chemical
3.) Bread dough rises when yeast is added-chemical
4.) Sugar dissolves in water-physical
Think of it this way- if it's a chemical change, you can't change the object back to the way it was before the change. So, if you bend a copper wire, you can bend it back=physical change. If you burn charcoal, it's permanently become another form=chemical.
1. physical
2. chemical: the object's properties changed, can't be changed back
3. Chemical: yeast is catalyst for change, can't be changed back.
4. physical: still just water and sugar.
1.) Physical
2.) Chemical- it's being oxidized
3.) Physical- it's just being inflated with CO2 from the yeast (I think)
4.) Physical, the sugar just dissolved, but its still the same
1.physical
2.chemical
3.chemical
4.physical
1. physical
2. chemical
3. chemical
4. physical

chemical changes cannot be restored to its original matter composition.
well i'm pretty sure:
1-physical
2-chemical
3-chemical
4-chemical
1. Neither; it's a mechanical change.
2. Chemical -- combustion.
3. Chemical. The yeast turns starch into carbon dioxide.
4. Physical.

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