PERIODIC PROPERTIES

A. Atomic radius

The distance between the center core and outer shell.

Positive charge that is felt by electrons called the effective nuclear charge. The larger the effective nuclear charge, the more attracted by the nucleus. Basically cations have smaller radii while the anion has a larger radius.

B. Ionization potential - ionization energy

Ionization energy is the energy required to release one electron in the outer shell (valence electrons) of atoms or elements in a gaseous state. Ionization energy will be even greater if the effective nuclear charge larger or smaller atomic size.

C. electron affinity

Electron affinity is the energy released when an atom or ion in a gaseous state capture electrons from the outside. Generally negative electron affinity (energy released), but in some atoms have an electron affinity is positive. The smaller the size of atoms, electrons are captured will be closer to the nucleus, the energy liberated as a result will be even greater.

D. electronegativity

Electronegativity is the tendency of an atom to attract electrons (the tendency to be negative ions).

E. basicity

Power of an atom to be acidic or alkaline.

F. reactivity

Reactivity of an element associated with later elements of the release or capture of electrons. Elements of class IA and VIIA is the most reactive element. In group IA, the more downward the more reactive but otherwise in group VIIA is getting to the bottom of the less reactive.