Which of the following is not an example of a chemical change?

digesting food
burning gas in an engine
cooking eggs
grinding pepper

Find the mass, in grams, of 5.00*10^23 molecules of f2

Suppose you mix one mole of sulfuric acid (h2so4) with 1 mole of sodium hydroxide(naoh). why does the ph of the solution remain below 7? ( explain so i can get better understanding! )

Name atleast 3 type of energy associated with the microwave