А city's water supply is fluoridated by adding NaF. The desired concentration of F is 1.6ppm. How many
mg of NaF should be added per
gallon & of
treated water if the water supply
is 0.2 ppm in F-?​

samuel de champlain. in 1608, king henry iv sponsored pierre dugua, sieur de mons and samuel de champlain as founders of the city of quebec with 28 men. this was the second permanent french settlement in the colony of canada.

a boiling water reactor does not boil the water. a pressurized water reactor boils the water faster. a pressurized water reactor is heated directly by the core. a pressurized water reactor does not use fission.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

elements make up everything, and they combine to make compounds.

the answer is c