A chemist mixed two substances together: a blue powder with no smell and a colorless liquid with a strong smell. Their repeating groups of atoms are shown above on the left. After they were mixed, the chemist analyzed the results and found two substances. One ending substance had the repeating group of atoms shown above on the right. Is the ending substance the same substance as the blue powder? What happened to the atoms of the starting substances when the ending substances formed? Be sure to explain your answers to both of these questions.

 ctu

Explanatio

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.