Electronic Structure of the Atom

In this Chapter, we have learned the energy level of the electrons surrounding the nucleus. Different elements have different electronic energy level. An Energy Level is the amount of energy, which an electron in an atom can possess. ("n" is the number of the energy level). The energy difference between two particular enegy level is called the quantum of energy.

                                                                What is energy level?

Quantum of energy

In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure. It concerns the way electrons can be distributed in the orbitals of the given system (atomic or molecular for instance).

For example:  H hydrogen is 1s¹
                              C carbon is 1s² 2s² 2p²
                      Mg magnesium is 1s² 2s² 2p⁶ 3s²
                            

Ground State：
when all the electrons of an atom are in their lowest possible energy levels

Excited State:

when one or more of an atom's electrons are in energy levels other than the lowest available level.

Types of Orbitals:

An atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term may also refer to the physical region defined by the function where the electron is likely to be.

Predicting the Number of Valence Electrons:

In chemistry, valence electrons are the electrons of an atom that can participate in the formation of chemical bonds with other atoms. Valence electrons are the "own" electrons, present in the free neutral atom, that combine with valence electrons of other atoms to form chemical bonds. In a single covalent bond both atoms contribute one valence electron to form a shared pair. For main group elements, only the outermost electrons are valence electrons. In transition metals, some inner-shell electrons are also valence electrons.

The videos below are examples of how to find valence electrons from the electron configuration:

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