Chapter 4 Chapter 4.2 Quantum Theory - describes mathematically the wave properties of electrons and other vary small particles (Schrodinger) Atomic Orbital - area where an electron can be found Quantum Numbers - are numbers that specify the properties of atomic orbitals and their electrons. The 1st 3 Quantum Numbers indicate the region occupied by a given orbital in terms of:
Whole numbers and relate to each other. The 4th quantum number has only 2 values and is needed to specify one of two possible orientations of and electron within an orbital. Principal Quantum Number - symbolized by n, indicates the main energy levels surrounding a nucleus.
Orbial Quantum Number - indicated the shape of an orbital *each main energy level - different shapes - occupy different regions  * regions are called sublevels or subshells table 4.1 p 109 The number of sublevels = the principal quantum number 1st 4 numbers - s, p, d, f s - lowest enrage level, spherical in shape p - dumbbell shape d - dumbbell shape - 4 lobes f - very complex Number of Sublevels in each energy level: 1st energy level - 1 sublevel - s 2nd energy level - 2 sublevels -s,p 3rd energy level - 3 sublevels - s,p,d 4th energy level - 4 sublevels s,p,d,f n = the # of sublevels Magnetic Quantum Number - indicates the orientation of an orbital about the nucleus s sublevels - possible orientation - only 1 s sublevel in each energy level p sublevels - 3 different orientations - (x, y, z) - each sublevel contains 3 different p orbitals - p p p d sublevels - 5 different orbitals in each d sublevel, table 4.16 p. 110 f sublevels - 7 different orbitals in each f sublevel The # of orbitals in each main energy level equals the square of the principal quantum number (table 4.1) Spin Quantum Number - has only 2 possible values (+ 1/2 or - 1/2) - which indicate 2 possible states of an electron in an orbital.
Each orbital can hold up two electrons - having opposites spins. 1st energy level - 1 s orbital - contain 2 electrons - one sphere 2nd energy level - 1s orbital - 2 electrons - 3p orbitals - 6 electrons - total 8 electrons 3rd energy level - total 18 electrons |