Hydrogen spectrum short questions

Question: Why the energy of violet colour is greater than red colour in visible region? Answer: Energy of voilet colour is greater than that of red colour because wave length of voilet colour is relatively shorter (i.e. 400-430nm) as compared to wave length of red colour (i.e. 620-800 nm). Since energy is inversely related to wave length of radiation.i.e E=hc/ λ. So, energy of violet light is greater than that of red light.

Question: Why the photographic plate is white and few dark lines are there in the line absorption sepectra of substance?Answer: When a beam of white light is passed through a gaseous sample of an element, element absorbs certain wave length, while rest of wave lengths pass through it. The wave lengths of radiation that have been passed appear on photographic plate as white lines, whereas the wave lengths which have been absorbed are absent and in their splaces, dark lines appear.

Question: Why the photographic plate is dark and few white lines are there in the line emission sepectra of substance?
Answer: When elements in solid or gaseous state are heated to high temperature, or subjected to an electric discharge. The radiation of certain wave lengths are absorbed by the element atoms. The radiations of these absorbed wave lengths are then emitted. These emitted radiations of certain wave length appeared on photographic plate as bright lines and remaining photographic plate is dark.

Question: How is atomic emission spectrum obtained?
Answer: When elements in solid or gaseous state are heated to high temperature, or subjected to an electric discharge. The radiation of certain wave lengths are absorbed by the element atoms. Actually these absorbed radiations cause the electronic excitation. The radiations of these absorbed wave lengths are then emitted due to de-excitation of electrons in the atom . These emitted radiations of certain wave length appeared on photographic plate as bright lines and remaining photographic plate is dark.

Question: Indicate the limiting line of Balmer series.
Answer: When the electrons jump form an infinit to n = 2 of hydrogen atom then this line on the photographic plate is called limiting line. It has high energy.

Question: What is H_α-line in the hydrogen spectrum?
Answer: This is first line of Balmer series. It is produced due to the jumping of the electrons from n=3 to n = 2. This line lies in the visible region. Next

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