Question

what do these two changes have in common? a piece of apple turning brown making jam select all that apply. both are only physical changes. both are chemical changes. both are caused by heating. both are caused by cooling.

Explanation:

When an apple turns brown, it is due to a chemical reaction (oxidation) between the apple's enzymes and oxygen in the air. Making jam involves heating fruits with sugar which causes chemical changes like the breakdown of pectin and caramelization of sugar. These are not just physical changes as new substances are formed. Heating is involved in making jam but not the main cause of an apple turning brown. Cooling is not the cause for either of these changes.

Answer:

Both are chemical changes.