A wavelength of 656.3 nm is emitted by the hydrogen atoms in a high-voltage discharge tube. What are the initial and final values of the quantum number n for the energy level transition that produces this wavelength?

Answer : The initial and final values of the quantum number is, 2 and 3

Explanation :

Assumption : We have to determine the value of wavelength when electron will jump from 2 to 3 level.

Using Rydberg's Equation:

Where,

= Wavelength

= Rydberg's Constant  =

= Higher energy level = 3

= Lower energy level = 2

Putting the values, in above equation, we get

From this we conclude that the calculated value of wavelength is equal to given value of wavelength.

Therefore, the initial and final values of the quantum number is, 2 and 3

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o