Arrangement Of Electrons In The Atoms
Electrons are negatively charged, so they form a cloud of negative charges outside the nucleus. In this cloud, the electrons are arranged according to their potential nergy in different energy levels or shells. The energy levels of the electrons are denoted by the numbers 1, 2, 3, 4, 5 and 6 whereas shells are represented by the letters K, L, M, N, O and P.
1st energy level is K shell
2nd energy level is L shell
3rd energy level is M shell
4th energy level is N shell,and so on.
The energy levels or shells are represented by circles around the nucleus. The shells are counted from the centre outwards (see Figure 22).For example, K shell having the minimum energy is nearest to the nucleus ; L shell which has a little more energy is a bit farther away from the nucleus, and so on.It is obvious that the outermost shell of an atom is at the highest energy level.
We will now describe how the electrons fill up the various energy levels or shells in an atom. It is a well known fact that a system is most stable when it has the minimum energy.So, the electrons occupy the low energy levels first (this will make the atoms more stable). Now, K shell is at the lowest energy level, so first of all the electrons fill K shell, then L shell, M shell, N shell,and so on.
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Structure of the Atom - Notes
1. Drawback of Rutherford’s Model of the Atom
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2. Rutherford’s Experiment - Discovery of Nucleus
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3. For the symbols H, D and T,tabulate three sub-atomic particles found in each of them.
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5. Structure of The Atom - Study Points
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10. Arrangement Of Electrons In The Atoms
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13. Limitations of Rutherford's model of the atom
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15. All about Names of the Chemical Elements
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17. How to learn naming Chemical Formulae?
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20. Comparison between Proton, Neutron and Electron
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21. Electronic Configurations of First 20 Elements
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26. Rules for writing of distribution of electrons in various shells for the first 18 elements
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35. The Physical Properties of the Isotopes of an Element are Different
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39. All the Isotopes of an Element Have Identical Chemical Properties
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42. Relationship Between Mass Number and Atomic Number
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44. Valaence Electrons (Or Valancy Electrons)
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45. Electronic Configurations of Noble Gases (or Inert Gases)
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48. Reason for the Fractional Atomic Masses of Elements
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49. Applications of Radioactive Isotopes
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50. Relation Between Valency and Valence Electrons
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