Which change occurs when an atom in an excited
state returns to the ground state?
(1) energy is emitted.
(2) energy is absorbed.
(3) the number of electrons decreases.
(4) the number of electrons increases.

i believe it is 40–40–20%

explanation:

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.