THE HUND’S RULE

• The Rutherford’s model of the atom consists of nucleus and electrons only
• The Bohr’s model is created in the year 1913
• Niels Bohr is a Danish Physicist who proposed the quantum model of Hydrogen
• electrons move around the nucleus
• each orbit is given a quantum number
• Electron configuration refers to how electrons are distributed on the various atomic orbitals
• there are 7 orbitals that correspond to 7 periods
• The Pauli exclusion principle states that no two electrons in an atom can have the same four quantum numbers
• Each atomic orbital in an atom is characterized by a unique set of quantum numbers
• This quantum number designates the size of an orbital
• The principle quantum number is represented by "n"
• principle quantum numbers only go up to 7
• Angular or Azimuthal momentum quantum numbers describes the shape of an orbital
• Angular momentum quantum numbers is represented by "l"
• Magnetic quantum numbers describe the orientation of an orbital in space
• Magnetic quantum numbers are denoted as "ml" and have values of -3,-2,-1 or 1,2,3
• Electron spin quantum numbers describes the spin of an electron that occupies a particular orbital
• Electron spin quantum numbers are denoted by "ms" and has values of -1/2 and 1/2 only
• The Aufbau principle states that electrons fill according to orbital energies, from lowest to highest
• Aufbau is a German term which means "building up" or "construction"
• The hund's rule is the most stable arrangement for electrons in orbitals of equal energy, it uses boxes and arrows
• the number of arrows should be equal to the number of electrons
• Quantum numbers are used to describe the position and energy of electrons in an orbit