How did Wegener explain the fact that Lystrosaurus fossils, an ancient land reptile, showed up on different continents? The continents were at one time joined together.

The fossils were moved by humans.

The Lystrosaurus swam between the two continents.

The fossils must be of different species.

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.