i think it is 6 valence electrons
Answer: 13.9 g of 
will be produced from the given mass of oxygen
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
7 moles of 
produce = 6 moles of
Thus 0.900 moles of will produce =
of
Mass of 
Thus 13.9 g of will be produced from the given mass of oxygen
The formula we can use here is the Plancks equation:
E = h c / ʎ
where h is Plancks constant = 6.626 × 10-34 m2 kg / s, c
is speed of light = 3 x 10^8 m/s and ʎ is wavelength = 656.1 x 10^-9 m
Therefore E is:
E = (6.626 × 10-34 m2 kg / s)
* (3 x 10^8 m/s) / 656.1 x 10^-9 m
<span>E = 3.03 x 10^-19 J</span>
