Nitrogen can ionically bond with an unknown element x from group 2. how many ions of element x are required to create a stable ionic compound with nitrogen? a) 2 b) 3 c) 4 d) there is not enough information.

Answer is: B) 3.

Nitrogen (nonmetal) in this compound has oxidation number -3 and element X (metal) has oxidation number +2.

Smallest common multiple for 3 and 2 is 6.

number of nitrogen atoms = 6 ÷ 3.

number of nitrogen atoms = 2, there are two nitrogen atoms.

number of atom X: 6 ÷ 2 = 3.

For example, Mg₃N₂ is magnesium nitride. Nitrogen has -3 oxidation number and magnesium has oxidation number +2.

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.