Atomic Physics is one of the easiest Chapters of JEE syllabus. So, XI std students, make thorough these formulae. Written after the request of Ishan.Maheswari.

1) De Broglie's Eqn.:  (Wave particle duality)

 = h/mv

2)Plank's eqn.

E= h=hc/  

3)Bohr's Conditions:

i)mvr=nh/2

ii)E₂-E₁=h

4) Radius of nth orbit:

r_n= n² * 0.53 *10 ^{-10 m}

5) Energy of nth orbit:

E_n= -13.6/n²   eV         1eV= 1.6 * 10 ^-19 J

6)Frequency of Spectral lines:

 ^-1 =R [n₁ ^-2 -n₂ ^-2]   R=Rydberg's Constant = 1.094 * 10 ^-7 m ^-1

 

For Lyman, Balmer, Paschen, Brackett, Pfund Series, n₁= 1,2,3,4,5. n₂>n₁

7) Photo-electric Effect:

h=h_o + mv²/2 ,where, h_o = W =Work function. _o = Threshold (min.)freq.

(Point out any mistakes and rate me if u find this useful)