Question

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

Answer 1

A resposta certa é a letra A: Li20 ( Pois é oxídio de lítio )

Answer 2

Answer: A)
`Li_2O`

Step-by-step 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
`Li^+`.

`Lithium(Li):3:1s^22s^1`

Oxygen is a non metal with 6 valence electrons to give
`O^(2-)`

`Oxygen(O):8:1s^22s^22p^4`

They combine to form
`Li_2O`.