5_notes chemistry!! review

5_notes chemistry!! review - CHEM 2AP UNIT 5 CH. 7 Quantum...

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UNIT 5 CH. 7 Quantum Mechanics 16 10/27/2002 THE 4 QUANTUM NUMBERS ( n, l, m l , m s ) THE PRINCIPAL QUANTUM NUMBER ( n ) Designates the main energy level (floor) or shell. Values: 1, 2, 3, ……. . n = 7 is the highest number of shell used for the atoms known. Describes the CLOUD SIZE . The larger the value of n , the larger the cloud size. Energy levels closer to the nucleus have lower energy. As n increases, the orbital becomes larger and the electron spends more time farther from the nucleus. An increase in n also means that the electron has a higher energy and is therefore less tightly bound to the nucleus. The larger n is, the greater the average distance of an electron in the orbital from the nucleus and therefore the larger (and less stable) the orbital. The maximum number of electrons possible in a given shell is 2 n 2 . LEVEL MAXIMUM NO. OF ELECTRONS 2n 2 n = 1 2 n = 2 8 n = 3 18 n = 4 32 n = 5 50 n = 6 72 n = 7 98 In reality there are only 32 electrons in levels 5, 6, and 7 because of the number of different elements discovered or man-made. ANGULAR MOMENTUM QUANTUM NUMBER ( l ) Designates the sub-level (apartment) where the electron can be found. Gives the SHAPE OF THE ORBITALS . Values of l: from 0 to ( n -1) for each value of n. The value of l for a particular orbital is generally designated by the letters s , p , d , and f corresponding to l values of 0., 1, 2, and 3. for the known atoms, only s, p, d , and f exist. Value of l 0 1 2 3 4 5 Sub-level s p d f g* h* *These sublevels are not used in the ground state of any known element. Each sublevel is given a letter designation (like s) and a number designation (s = 0). This allows you to put these two quantum numbers together to identify the shape and location of the atomic orbital.(1s, 4f, 3d etc.) MAGNETIC QUANTUM NUMBER (m l ) Designates the orbital (room) where the electron can be found. Gives the DIRECTION IN SPACE that the orbital takes. m l specifies to which orbital within a subshell the electron is assigned. Orbitals in a given subshell differ only in their orientation in space, not in their shape. Values of m l : from – l , ….0, ….+ l . The middle orbital of a subshell has a value of 0. Orbitals to the left of the middle orbital have negative numbers; to the right, they have + numbers. m
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5_notes chemistry!! review - CHEM 2AP UNIT 5 CH. 7 Quantum...

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