Which element is present in all amino acids but not necessarily in fats or carbohydrates?

Find the mass, in grams, of 5.00*10^23 molecules of f2

Anurse used a 0.02-mg/l solution of disinfection to clean a patients wound. what is the concentration of the solution expressed as a percentage?

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium.b)heavier than helium.c)the same weight as helium.d)dependent on the element that reacted with carbon.