Respuesta :
That is not true at all. Sorry for being rude but for 3 the answer is b because there is not always a release of gas. It is not a because energy is used to start the reaction to get over the hump. For number 4 it is c i can not really explain because this is just what i know.
QUESTION 3:
There are signs that you can look for to helpyou determine whether a chemical reaction has taken place. You’ll wantto be on the lookout for:
1. Color changes
2. Precipitation of a solid
3. Energy changes (in other words, heat or light is absorbed orreleased)
4. Odor changes
5. Gas release
The right answer is D. a change of state.