What is the molar mass of (nh4)2so4

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

How many moles of oxygen react with 12 moles of aluminum

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions