Question

in the illustration, o is color - coded as red. is the change represented by the following illustration best categorized as a chemical change or a physical change? use the references to access important values if needed for this question.

Explanation:

Step1: Identify change type

In a chemical change, new substances are formed with different chemical properties. In a physical change, the substance's chemical identity remains the same, only its physical state or appearance changes. Here, the molecules of oxygen (initially as $O_2$) are broken down into individual oxygen atoms. But no new chemical - substance is formed overall, just a change in the form of oxygen.

Step2: Determine change category

Since the oxygen atoms are still oxygen (same chemical identity), and only the bonding between atoms has changed (from di - atomic molecules to individual atoms), this is a physical change.

Answer:

Physical change