Name three elements that are likely to react in a similar way to: a sodium b fluorine

sodium - The ones "most" similar would be the ones closest in mass as well. Those would be Lithium (Li) and Potassium (K). Of those, I would consider Lithium to be "closest" as it shares the higher reactivity with sodium compared to the heavier elements in the Group.

fluorine - oxygen , chlorine and uranium are the most known elements that are likely to react in a similar way.

Explanation:

hope it helps

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.