Sodium fluoride (NaF) is added to drinking water in some municipalities to protect teeth against cavities. The idea is to convert hydroxyapatite, Ca10(PO4)6(OH)2, into more stable fluorapatite, Ca10(PO4)6F2. The molar mass of hydroxyapatite is 502 g/mol. What is the molarity of a 10.0 mg/L sodium fluoride solution

thats a little if u want the answer just look it up on google thats what i do haha : )

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.

level 4 to level 2 : ))

it's c (engineer's do their work with mechanical stuff not on any living being)