Periodic Trends

Electronegativity

The strength an atom pulls on its own electrons and attracts electrons from other atoms in a chemical bond; it increases across a period and decreases down a group.

Ionization energy

How much energy is required to remove an electron, it decreases down and increase to the right

Metallic character

The tendency to lose an electron and form positive ions, which increases down a group and decreases across a period.

Electron Affinity

How readily an atom accepts an electron to form a negative ion; it generally increases across a period and decreases down a group.

Reactivity

How likely an atom is to form bonds with other atoms, increasing down a group and decreasing across a period. for non metals it increases to the right, for metals it increase to the left

Atomic Radius

Distance from nucleus to outermost shell of an atom's electrons; it generally increases down a group and decreases across a period.

Ionic Radius

Distance between nucleus and outermost shell of the atom’s most common ion; it varies depending on the ion's charge, typically increasing for anions and decreasing for cations compared to the atomic radius.

effective nuclear charge

The charge experienced by the valence electrons is the attraction of the protons in the nucleus minus the core electrons. increase going to the right, stay the same going down

Shielding Effect

repulsion by core electrons, increases going down, stays the same going to the right