What do these two changes have in common? a piece of avocado turning brown a log decomposing in the woods Select all that apply. Both are only physical changes. Both are chemical changes. Both are caused by heating. Both are caused by cooling.

## Step 1<br />The problem presents two scenarios: a piece of avocado turning brown and a log decomposing in the woods. We are asked to identify the commonality between these two changes.<br /><br />## Step 2<br />The first scenario involves an avocado turning brown. This is a result of a chemical change known as enzymatic browning. This process occurs when the enzyme polyphenol oxidase (PPO) in the avocado reacts with oxygen in the air, leading to the formation of brown pigments.<br /><br />## Step 3<br />The second scenario involves a log decomposing in the woods. This is also a chemical change. Decomposition is a process where organic substances are broken down into simpler organic matter. This process is facilitated by the action of microorganisms and is a chemical change.<br /><br />## Step 4<br />By comparing the two scenarios, we can see that both involve chemical changes. Neither of these changes is caused by heating or cooling.