CH110 Lecture Notes - Lecture 4: Pauli Exclusion Principle, Periodic Trends, Atomic Number
Document Summary
The periodic table is a way to organize the known elements. The periodic table is based on electron arrangements in atoms. When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically . The periodic table lists elements (left to right) in order of increasing atomic number (z) Since #e = z (for a neutral atom) the periodic table lists atoms in order of increasing e . Because the elements are also arranged by column. Elements in columns display similar electron arrangements and chemical patterns. Each electron in an atom has a unique set of quantum numbers. Each electron in an atom is in an orbital. The first three quantum numbers specify the orbital ( n, l, ml ) The fourth quantum number (ms) specifies the spin of the electron ( 1 2 or +1 2 ) Since only two choices for the spin of an electron, only two electrons in an orbital.
