SCIENCE PRESENTATION

• Bulosan Luis Miguel
• 8-Kowalski
• Mr. Jc Oliquino

QUESTIONS

• Orbitals
• Number of orbitals per sublevel
• Orbital diagram
• Hund's rule (Frederick hund)
• Pauli exclusion principle (Wolfgang pauli)

ORBITALS

• When a planet moves around the sun, you can plot a definite path for it which is called an orbit. A simple view of the atom looks similar and you may have pictured the electrons as orbiting around the nucleus. The truth is different, and electrons in fact inhabit regions of space known as orbitals. Orbits and orbitals sound similar, but they have quite different meanings. It is essential that you understand the difference between them.

NUMBER OF ORBITALS PER SUBLEVEL

• s 1 orbital with 2 electrons p 3 orbitals with 6 electrons f 5 orbitals with 10 electrons d 7 orbitals with 14 electrons

ORBITAL DIAGRAML

HUND'S RULES

• Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin). When assigning electrons to orbitals, an electron first seeks to fill all the orbitals with similar energy (also referred to as degenerate orbitals) before pairing with another electron in a half-filled orbital.

HUND'S RULE

• Atoms at ground states tend to have as many unpaired electrons as possible. In visualizing this process, consider how electrons exhibit the same behavior as the same poles on a magnet would if they came into contact; as the negatively charged electrons fill orbitals, they first try to get as far as possible from each other before having to pair up.

PAULI EXCLUSION PRINCIPLE

• The Pauli exclusion principle is part of one of our most basic observations of nature: particles of half-integer spin must have antisymmetric wavefunctions, and particles of integer spin must have symmetric wavefunctions. The minus sign in the above relationship forces the wavefunction to vanish identically if both states are "a" or "b", implying that it is impossible for both electrons to occupy the same state.