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? Calculate the radius of Bohr’s fifth orbit for hydrogen atom.





Q.16:- (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.

 

Answer:-
(i) En = -21.8×10-19/n2 J
∴ E= -21.8×10-18/52 J = 8.72×10-20 J
(ii) For H atom, rn = 0.529×nÅ
∴  r= 0.529×5= 13.225 Å = 1.3225 nm