How do you know when a chemical change has occurred?

Answer 1

There are many ways

• if something is burned (not heated or melted but burned)
• if something changes color
• if something spoils or tarnishes
• if something does not go through a stage of matter such as melting, freezing, evaporating, condensing, sublimating
• if something does not just dissolve
• if something can not be separated in any way

Answer 2

A physical change is something simple, or easy to reverse, like a change of state (Such as ice melting into water)

A chemical change is something difficult to reverse. Indicators of a chemical change can include:-a change of colour; - a percipitate forming; - heat or light being given off or; - a change in odour

I hope that helped

Answer 3

Some indicators of a chemical reaction are:
- formation of new compounds
- change of color
- change of odor
- release of a gas
- change of the temperature
- change of the viscosity
- formation of a precipitate
- change of general appearance
- possible explosion
- possible chemiluminescence

Answer 4

You know if a chemical change has taken place because if it has then it will change colour

I looked this up when I was doing exam study in year 8

Answer 5

Some indications are: change of color, change of odor, formation of a precipitate, relese of a gas, change of pH, a violent reaction, formation of new compounds, etc.

Answer 6

the substance changes colour, bubble or gas are produces, heat light or sound is produced, a change in temperature, or a different smell or taste.

Answer 7

by change in heat or light or formation of precipitate or change in colour or odour.

Answer 8

The signs of a chemical change include:

formation of a precipitate

formation of a gas

change in temperature

change in color

Answer 9

change in odor, change in color.