5. describe a chemical indicator. what is it? what is it used for? how does it work?

Litmus paper , determine the acidity/alkalinity of a solution ,turns red on acids and blue on alkaline while naturally purple .

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.