Please help me with this question it’s really confusing and I’ll give you extra credit :))

Which real-world scenarios below represent physical and chemical changes? -running a car -exploding fireworks -mixing water and powdered drink mix -combining oil and vinegar to make salad dressing -taking aspirin for a headache -diluting bleach with water-digesting dinner-spreading peanut butter on bread

What type of matter is made of only one kind of atom

What type of organic molecule comprises the majority of a potato?