Mixing the chemicals caused them to absorb heat. A chemical reaction took place. New elements were formed. The procedure caused a gas to be formed.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Mixing baking soda and vinegar makes the temperature of the solution decrease and release carbon dioxide. Which conclusion about this investigation is not valid?
Possibilities:
- Mixing the chemicals caused them to absorb heat.
- A chemical reaction took place.
- New elements were formed.
- The procedure caused a gas to be formed.

New elements were formed.