Lithium is a metal with an oxidation number of 1+ and oxygen is a nonmetal with an oxidation number of 2-. which chemical formula represents the compound formed by these two elements? a) li2o b) li3o c) lio d) lio2

A)

Explanation: In order to form a neutral compound the charges must be balanced. Thus in order to neutralize the 2- charge on oxygen atom, two atoms of lithium with +1 charge must combine.

Lithium is a metal with one valence electron to form .

Oxygen is a non metal with 6 valence electrons to give

They combine to form .

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.

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.