4.77g of an oxide of copper contains 3.81g of copper. calculate the empirical formula for the compound

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

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.

What happens when light is scattered?