(i) The energy associated with the first orbit in the hydrogen atom is –2.18 × 10–18 J atom–1. What is the energy associated with the fifth orbit?

(ii) Calculate the radius of Bohr’s fifth orbit for hydrogen atom.


(i) Energy of an electrons = - (2.18× 10-18)/n2

Where n = principal quantum number


Now the Energy associated with the fifth orbit of hydrogen atom is


E5 = -(2.18× 10-18)/(5)2 = -2.18× 10-18/25


E5 = -8.72 × 10-20J


(ii) Radius of Bohr’s nth for hydrogen atom is given by,


Rn = (0.0529nm) / n2


For,


N = 5


R5 = (0.0529 nm) (5)2


R5 = 1.3225 nm


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