Atoms

From basics.

Using, where = 2 and
Then,

E = = 3.4 eV

Here, and

In vacuum all waves have same velocity m

Here Half life = = 6 hr.

(A - 4), ( Z - l )

becquerel.

About 0.23 amu is lost in fission of so mass changed in enrgy = = 0.1%

N =
decayed = 63% ( e = 2.718)

For first line of Lyman series,
and


For first line of Paschen series and

The radius of the atomic nuclei is directly proportional to cube root of Mass number (Z)

In Raman effect, Stokes? lines are spectral lines having lower frequency or greater wavelength than that of the original line.

Hydrogen atom does not emit -rays because its energy levels are too close to each other.

Let initial activity of both substances are same.

Here,

or or
or

Incandescent electric lamp produces continuous emission spectrum whereas mercury and sodium vapour give line emission spectrum. Polyatomic substances such as and produces band absorption spectrum.

For a ruby laser, a crystal of ruby is formed into a cylinder. A fully reflecting mirror is placed on one end and a partially reflecting mirror on the other. A high-intensity lamp is spiraled around the ruby cylinder to provide a flash of white light that triggers the laser action. The green and blue wavelengths in the flash excite electrons in the chromium atoms to a higher energy level. Upon returning to their normal state, the electrons emit their characteristic ruby-red light. The mirrors reflect some of this light back and forth inside the ruby crystal, stimulating other excited chromium atoms to produce more red light, until the light pulse builds up to high power and drains the energy stored in the crystal. In ruby laser stimulated emission is due to transition from metastable state to ground state.

Number of spectral lines obtained due to transition of electrons from th orbit to lower orbit is,

I case

II case

Velocity of electron in hydrogen atom in th orbit

Flash spectrum confirms a total soldar eclipse.

Spectrum of sunlight is line absorption spectrum.

Time period of revolution,
Frequency of revolution ,
f \propto\frac{1}{n^{3}}\)