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In This Part :
The energy levels
They are imaginary regions (places) around the nucleus in which the electrons move according to their energies.
-The maximum number of energy levels in the heaviest (largest) atoms is seven.
- The energy levels are arranged from the nucleus as follows :
- Each energy level can take a definite number of electrons.
- The number of electrons which saturates the first four energy levels can be calculated
from the relation 2n2 , where (n) is the number of the energy level.
Electronic configuration according to the relation 2n2 :
• The electrons are distributed in the 1st level "K" (the least energy), then the seco
nd and so on.
If the symbol of the element was :
- One letter : It is written in capital.
- Two letters : The first is written in capital and the second in small.
Some elements are common in their initial letters, so the second letter is taken to differentiate between them, like :
*Carbon (C) and Calcium (Ca) . * Sulphur (S) and Silicon (Si).
* Hydrogen (H) and Helium (He).
The element symbol is derived from its Latin name,
so that symbols of some elements differ from their names in English language.
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مستر احمد الباشا
