Calculate the value of ni for Hydrogen if a violet line from the Balmer series has a recorded wavelength of 410 nm.

Solution :

Given that the violet line from Balmer series having a recorded wavelength of 410 nm. As the recorded wavelength is 410 nm we know, the wavelength range of violet light is 380 nm -450 nm. So the 410 nm is corresponding to violet light wavelength.

We know, among all the series of lines spectrum of atom, only the Balmer series are in visible range. For Balmer series, the equation of wavelength associated with the e-transition of n = 2 orbit to n > 2 is

where, R = Rydberg constant = 109678 per cm

            λ = wavelength

Here the recorded λ = 410 nm =

∴

≈ 36

n = ±6

Here, n is the principle quantum number. It cannot be negative, so the value of n = 6 for hydrogen atom if the violet line from Balmer series that has a recorded wavelength of 410 nm.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.