Question

cutting an apple in half.
a physical change
b chemical change
pregunta 9 (1 punto)
is this a chemical or a physical change?
letting the cut apple sit out in the open air, causing it to turn brown over time.
a physical change
b chemical change
pregunta 10 (1 punto)
is this a chemical or a physical change?
when vinegar and baking soda are mixed together they generate a whole bunch of bubbles very quickly.
a chemical change
b physical change

Explanation:

1. Cutting an apple in half only changes its physical form, not its chemical composition. So it's a physical change.
2. When a cut - apple turns brown in the open air, it's due to a chemical reaction (oxidation) between the apple's compounds and oxygen in the air, so it's a chemical change.
3. Mixing vinegar and baking soda generates bubbles because a chemical reaction occurs, producing carbon dioxide gas. So it's a chemical change.

Answer:

1. a. Physical change
2. b. Chemical change
3. a. Chemical change