6. In the Middle Ages, most scientists believed that the world was made from four simple elements and that almost everything was a mixture.
Which type of pure substance had they not
yet discovered?
Plz help... I need this ASAP

ljjjljlj kjlk,ljym jlyu; jm; l mumytj

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.