What is the concentration in ppm (parts per million) if you dissolve 8.4 g of fertilizer in 244000 g of water?*
a. 34.4 ppm
b. 1.72x10 ppm
c. 17.2 ppm
d. 3.44x10-5 ppm

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

The boiling point of propanoic acid is higher than that of 1-butanol because: propanoic acid has a higher molecular weight than 1-butanol. propanoic acid is more soluble in water than 1-butanol. propanoic acid is a better hydrogen bond donor than 1-butanol. propanoic acid forms hydrogen bonded dimers and 1-butanol does not. 1-butanol forms hydrogen bonded dimers and propanoic acid does not.

The number at the end of an isotope’s name is the number.