Question

there are four sketches below. the first sketch shows a sample of substance x. the three sketches underneath show different changes to the sample. you must decide whether each of these changes is possible. if a change is possible, you must also decide whether it is a physical change or a chemical change. each sketch is drawn as if the sample were under a microscope so powerful that individual atoms could be seen. also, you should assume that the entire sample is in a sealed box, so that no matter can enter or leave. sample of substance x

Explanation:

• Change 1: In a chemical change, new substances are formed. Here, the atoms (represented by the colored spheres) combine in a different way, indicating a chemical reaction.
• Change 2: A physical change involves a change in the state or appearance of a substance without altering its chemical composition. But in this case, since new combinations of atoms (new substances) are formed (as seen from the new - colored sphere combinations), it is a chemical change.
• Change 3: No new substances are formed. The atoms just change their arrangement. In a physical change, the chemical identity of the substance remains the same. Here, the “atoms” (represented by the red spheres) only change their spacing and order, so it is a physical change.

Answer:

Change 1: a chemical change
Change 2: a chemical change
Change 3: a physical change