Which term identifies the dark smooth areas on surface of the moon

The dark smooth areas on the surface of the moon is called Maria.

Maria is made up of solidified lava which is a result of volcanic activity on the moon.

When Galileo observed these smooth dark spots on the moon he called them 'mare' which is latin for 'sea'. And the plural form of mare is 'maria'. Unlike Galileo predictions, recent investigations confirm that maria are not oceans but solidified lava.

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.