Select the correct answer.
Which statement best explains why this extrusive volcanic rock does not have visible crystals?

A.
It is homogeneous and composed of a soft mineral.
B.
It does not contain atoms of any Earth minerals.
C.
It cooled down before large crystals could form.
D.
It wasn’t exposed to friction during its formation.

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.

catya that's not even a b or c