At present, cosmologists expect the universe to

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

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium. b)heavier than helium. c)the same weight as helium. d)dependent on the element that reacted with carbon.

How many atoms or molecules are there in a mole of a substance?