3. Electron Structure of an Atom

yaboiemil's version from 2016-02-04 18:53

Quantum Numbers and their Meanings:


1. The state of each electron in an atom is determined by 4 quantum numbers:


Question Answer
Principal (n)Determines the total energy of the electron
Orbital (l)Determines the shape and symmetry of the orbital
Magnetic (m)Determines the orientation of the orbitals in space
Spin (s)Determines the actual momentum of an electron

Chill definitions for you to chill-ly learn:


Question Answer
Quantum NumberThe numbers that tell you about the state of an electron in an atom
Paulis exclusion principle2 electrons in an atom cannot be in the same state, must differ by at least 1 quantum no.


2. Electrons can be in the ground state with a minimum electron energy value,
or in an excited state where the electron energy value is greater. Ionization is the
extreme example, where an electron's energy is so great is can overcome the
nuclear attraction force and leave the nucleus, forming an ion.
3. The excited state lasts for a short amount of time (10-8 or 10-5seconds)
Some excited states have a higher probability of occurring, and so are deemed Metastable.
The atom can stay in this state for several minutes or hours.
4. The energy needed for atom ionization is also known as the binding energy/ionization energy (Ev)
If the atom receives more than this energy, the surplus is converted into kinetic energy
of the electron released
5. An atom will return to the ground state in order that the free electron will reoccupy the free
energy state. This will release a quantum (piece) of electromagnetic radiation in the process.
6. Electromagnetic radiation originating from this transition from metastable to ground state is
called Luminescence.
7. If it's short-term luminescence, then it's called Fluorescence
8. If it's long-term luminescence, then it's called Phosphorescence.


Question Answer
LuminescenceElectromagnetic radiation during a metastable ground state
FluorescenceShort-term luminescence
PhosphorescenceLong-term luminescence
Binding energyThe amount of energy used to hold the electron to the nucleus OR needed to ionize the atom
MetastableAn excited energy state that has a higher probability of occuring.

Recent badges