<u>Answer:</u> The longest wavelength of light is 656.5 nm
<u>Explanation:</u>
For the longest wavelength, the transition should be from n to n+1, where: n = lower energy level
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Higher energy level = 
= Lower energy level = 2 (Balmer series)
Putting the values in above equation, we get:

Converting this into nanometers, we use the conversion factor:

So, 
Hence, the longest wavelength of light is 656.5 nm
In order to determine the number of protons in 20.02 mol of Ne, we use Avogadro's number to convert the number of moles to number of atoms, 1 mol = 6.022 x 10^23 atoms. From there, we must know the number of protons in a Neon atom, which is 10. Thus, the formula will be:
(20.02 mol Ne)x(6.022 x 10^23 atoms/mol)x(10 protons/1 atom Ne) =
1.2056 x 10^26 protons
Answer:
Identify one disadvantage to each of the following models of electron configuration:
Dot structures
Arrow and line diagrams
Written electron configurations
Explanation:
Identify one disadvantage to each of the following models of electron configuration:
Dot structures
Arrow and line diagrams
Written electron configurations