The document discusses the structure of the hydrogen atom and its emission spectrum, specifically noting Rydberg's formula and the spectral lines resulting from electron transitions between energy levels. It outlines the Lyman series, the first spectral series of hydrogen discovered in the ultraviolet region, and describes Bohr's model of the atom, including the fixed orbits of electrons around the nucleus. Key points include the behaviors of electrons in different shells and their energy transitions.

1. Structure of the atom
.

2. Line spectrum of hydrogen
 Where, R is the Rydberg's constant, n is the initial energy level and n
₁ ₂
is the final energy level.
• The emission spectrum of hydrogen is divided into a number
of spectral lines with wavelengths given by the Rydberg
formula.
• These observed spectral lines are due to the electron making
transitions between the energy levels in an atom.

3. Emission & Absorption
Spectrum:

4. Spectra Lines Of Hydrogen
Lyman series
• It is first spectral series of H.
• It was found to be in ultraviolet region by
Lyman in 1898.
• For it value of n = 1 and n = 2, 3,
₁ ₂ 4
where 'n,' is ground state and 'n,' is called
excited state of electron present in a H-
atom.
• The wavelength of marginal line (i.e. n₂ = ∞ ) = for all
series. So for lyman series.
Line spectrum of hydrogen

5. Bohr’s model for hydrogen atom
• Atom is spherical and positive charge is present inside nucleus. Whereas
negative charge revolve around nucleus
• Electrons revolve around nucleus in fixed orbits called Shells or stationary
orbits. (K,L,M,N.....)
• Electrons do not emit or absorb energy while revolving in a shell.
(1ev = )
Where, z= Atomic no.
n= shell no.

6. • Electron release or absorb energy when it moves (jumps) from one shell to
another.
π
• Angular momentum of e- is integrel multiple of h/2π
• Radius of orbit

7. Thank you
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~MMAAP