Explain why the event in the picture takes place

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

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Word equation for k+ h2o yield koh + h2