KCET2017PhysicsNuclear Physics
The energy (in eV) required to excite an electron from ( n=2 ) to ( n=4 ) state in hydrogen atom is
Options
- A+ ( 2.55 )
- B- ( 3.4 )
- C( -0.85 )
- D+ ( 4.25 )
Correct answer
A. + ( 2.55 )
Step-by-step solution
In a hydrogen atom, energy required to excite an electron from state E₁ to state E_ f is E=E_ f -E_ i where energy of a state n is given by array l E_ n = -13.6 n² eV E₄= -13.6 42 = -13.6 16 =-0.85 eV and E₂= -13.6 2² = -13.6 4 =-3.4 eV array Therefore, E=E₄-E₂=-0.85-(-3.4)=(3.4-0.85) e ~V Thus, energy required =2.55 eV