Q.

An electron in a hydrogen atom makes a transition n1→n2, where n1 and n2 are the principal quantum numbers of the two states. Assume Bohr model to be valid.

  Column-I   Column-II
A) The electron emits an energy of 2.55 eV p) n1=2, n2=1
B) Time period of the electron in the initial state is eight times that in the final state q) n1=4, n2=2
C) Speed of electron become two times r) n1=5, n2=3
D) Radius of orbit of electron becomes 4.77 A0 s) n1=6, n2=3
    t) n1=8, n2=4

 

1 A→p,   B→p,t,   C→p,q,t,   D→r  
2 A→p,   B→p,t,   C→p,q,s,t,   D→r  
3 A→q,   B→p,q,s,t,   C→p,q,s,t,   D→r,s  
4 A→r,   B→p,   C→p,q,s,t,   D→q  

Ans.

(3)

En=-13.6Z2n2eV,  rn=0.529n2ZÅ,  Vn=2.2×106Znm/s,  T=2πrnvn.