Question

matter review
select the observations that might indicate a chemical change has occurred
phase change
formation of a substance in a different state
production of heat or light
breaking or melting
production of flames
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Explanation:

To determine which observations indicate a chemical change, we analyze each option:

• "Formation of a substance in a different state" is a physical change (phase change, like melting ice to water, no new substance formed).
• "Production of heat or light" is a sign of a chemical change (e.g., combustion, reactions that release energy as heat/light).
• "Breaking or melting" are physical changes (breaking is physical fragmentation, melting is phase change, no new substance).
• "Production of flames" is associated with combustion, a chemical change (new substances like CO₂, H₂O are formed).

So the observations indicating a chemical change are "Production of heat or light" and "Production of flames".

Answer:

Production of heat or light, Production of flames