Can someone please help

Which of the following ocean acidification? are the most likely side effects of a ph less than 7.0 in the ocean b. more metal salts altering the ocean chemistry c. dissolution of the shells of marine organisms d. both a & b e. all of the above.

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same

Stage in which a typical star has completely stopped fusion