Periodic Trends

atomic radius

distance from center to the outermost region

ionic radius

distance from center to the outer most region in ion

ionization energy

the minimum energy required to remove 1 mol of electrons from 1 mol of neutral gaseous atoms in

electron affinity

The change in energy released which accompanies addition of an electron to an atom in gaseous state

electronegativity

relative attractions that an atom has for a shared pair of electrons in a covalent bond

atomic radius trend

decreases across period from left to right, increase down group from top to bottom

ionic radius trend

radii of cations (e.g. Mg⁺) are smaller than their parent. radii of anions(e.g. Cl^–) are larger than their parent

ionization trend

increases across period from left to right, decreases down a group from top to bottom

electron affinity trend

increases across a period from left to right, decreases down a group from top to bottom

electronegativity trend

increases across period from left to right, decreases down a group from top to bottom

electron affinity equation

X(g)+e-=X^-(g)

ionization energy equation

X(g)=X^+ (g) + e-