8. Structure of Atom
1. The smallest unit of substances is called ________.
2. The central part of an atom is called _________.
3. Nucleus is made up of sub atomic particles like _________ and ________.
4. Visible light is an ____________ wave.
5. The speed of light (c) is _________ m/ s.
6. The electromagnetic energy is characterized by ________ and ______________.
7. A group of wave length or frequencies is called a _________.
8. The familiar example of the visible spectrum in nature is the formation of a ___________.
9. The range of wavelengths covering red colour to violet colour is called the ________________.
10. The entire range of wavelengths is known as the ___________.
11. In the equation E = hu, where ‘h’ is ___________ and ‘u’ is the frequency of light.
12. The value of h is __________ Js (Or) ____________ erg.Sec
13. Scientists found that each element emits its own characteristic colour. These colours correspond to certain discrete wavelengths of light and are called _________.
14. The states corresponding to these energies are called _____________ and the possible values of the energy is called energy levels.
15. The energy emitted by the electron is seen in the form of _______________ and when the wavelength is in the visible region it is visible as an emission line.
16. Bohr’s model explains all the line spectra observed in the case of _________ atom.
17. ___________ is a successful model as far as line spectra of hydrogen atom is concerned.
18. The line spectrum of hydrogen atom when observed through a high resolution ____________ appears as groups of finer lines.
19. Bohr’s model failed to account for splitting of ____________.
20. The nucleus of the atom is one of the principal foci of these ___________ orbits.
21. Somerfield was guided by the fact that, in general, periodic motion under the influence of a central force will lead to __________ orbits with the force situated at one of the foci.
22. _________ model failed to account for the atomic spectra of atoms of more than one
electron.
23. Max Karl Ernst Ludwig Planck was a German theoretical physicist who originated ______________ , which won him the Nobel Prize in Physics in 1918.
24. Planck made many contributions to theoretical physics, but his fame rests primarily on his role as originator of the ____________.
25. Electron revolves around the nucleus in defined paths called orbits or _________.
26. This short wavelength light interacts with the electron and disturbs the motion of the ___________.
27. Quantum mechanical model of atom was developed by ___________.
28. The region of space around the nucleus where the probability of finding the electron is maximum is called an _____________.
29. Each electron in an atom is described by a set of three numbers n, l, and ml.These numbers are called ______________.
30. Quantum numbersindicate the probability of finding the __________ in the space around the nucleus.
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