Type in the correct values to correctly represent the valence electron configuration of oxygen: asb2p
a=
b =
c =

A = 2s²

B = 2p⁴

or 2s² 2p⁴

Explanation:

Oxygen:

It is the eighth element of periodic table. It is present in group sixteen and second period of periodic table. It has six valance electrons. It is also called chalcogen because it is ore forming element. its atomic number is 8.

Electronic configuration:

O₈ = 1s² 2s² 2p⁴

The two electrons in 1s shell represent the core electrons while the six electrons in second shell are valance electrons.

Valance shell electronic configuration :

2s² 2p⁴

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2