Atomic Structure and Properties

1.7  Periodic Trends

Essential Knowledge:

*These are taken directly from College Board

◼ The organization of the periodic table is based on the recurring properties of the elements and explained by the pattern of electron configurations and the presence of completely or partially filled shells (and subshells) of electrons in atoms.  (SAP-2.A.1) 

WRITING THE ELECTRON CONFIGURATION OF ELEMENTS THAT ARE EXCEPTIONS TO THE AUFBAU PRINCIPLE WILL NOT BE ASSESSED ON THE AP EXAM. 

Rationale: The mere rote recall of the exceptions does not match the goals of the curriculum revision. 

◼ Trends in atomic properties within the periodic table (periodicity) can be qualitatively understood through the position of the element in the periodic table, Coulomb’s law, the shell model, and the concept of shielding/effective nuclear charge. These properties include:   (SAP-2.A.3)

a. Ionization energy 

b. Atomic and ionic radii 

c. Electron affinity 

d. Electronegativity.