Afood item that is left out of the refrigerator turns brown and forms bubbles and gas. what are the signs that this is a chemical reaction? check all that apply.

a: heat is produced.

b: heat is absorbed.

c: bubbles appear.

d: a precipitate forms.

e: the color changes.

The answers would be:

C. Bubbles appear

E. The color changes

If you'd like to know more, you can read on:

Although your selections are indications of chemical reactions, if you are referring to only the chemical reaction that occurred in your example, then the two answers are the only choices.

A chemical reaction occurs when the reactants form a new product. Signs of a chemical reaction include change is smell, color and temperature. In some cases, precipitate forms.

C: Bubbles appear E: The color changes.

Explanation:

A chemical reaction is defined as the reaction in which a change in chemical composition takes place. A new substance is formed in these reactions.

Example: Oxidation of iron to ferric oxide is a chemical change.

Here iron which is grey in color changes first to green and then turns brownish red.

Characteristics of a chemical reaction:

1. change in color

2. heat is gained or lost

3. evolution of gas

4. formation of precipitate

Thus when a food item that is left out of the refrigerator changes colour  and evolution of gas takes place and thus would be a chemical change.

scientific laws are the result of testing theories and proving them to be facts.

because if the tool that you are using is not balanced it there would be false mass.