How can you find the common denominator and least commom denominator? ? and thx i accedentaly clicked on the wrong subject

Common denominator - Find the Least Common Multiple of the denominators (which is called the Least Common Denominator).

Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.

Then add (or subtract) the fractions, as we wish!

Least common denominator - You do the same thing for the common denominator

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.