Why is electrolysis used to extract some metals

Very reactive metals, such as aluminium, form stable oxides and other compounds. Electrolysis is commonly used to extract these metals and requires a lot of electric current (energy) to reduce them to extract the metal. Less reactive metals, such as iron, form less stable oxides and other compounds.

Explanation:

Brainliest please?

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.