ALL Periodic Trends

the nuclear charge of a nucleus ______ left to right across a period and _____ down a period

increases, increases

Across a period shielding is _______ Down a group shielding _______

constant, increases

increasing atomic radius

down and to the left

increasing ionization energy

up and to the right including noble gases

increasing electronegativity

up and to the right, except noble gases

metals ____ e- and become ____

lose, +

nonmetals ___ e- and become _____

gain, -

cations are ___ than parent

smaller

anions are ____ than parent

larger

Anion

A negatively charged ion

Description of Atomic Radius Trend

Decreases across a period as increasing nuclear charge pulls in the electrons. Increases down a family as electrons are added to shells further from the nucleus

Cation

A positively charged ion

Effective Nuclear Charge

Positive charge that an electron experience from the nucleus.

Electron Affinity

Energy released when an atom or ion in the gaseous state gains an electron. Increases from left to right and from bottom to top on the Periodic Table.

Ionic Radius

Distance from the center of an ion's nucleus to its outermost electron

Ionization Energy (IE)

The amount of energy required to remove an electron from an atom.

Isoelectronic

Two different elements that share the same electronic configuration (ex K+, Ar)

Isoelectronic Series

Two or more different elements that share the same electronic configuration (ex K+, Ar, Cl-)

Shielding

An invisible force shield that keeps outer electrons away from the nucleus.

Electronegativity

Describes the ability of an atom to attract electrons towards itself in a covalent bond

Atomic Radius

Distance from nucleus to outermost electon

The Periodic Law

The properties of the elements are periodic or repeating functions of their atomic numbers.

valence electrons

What has the greatest influence on elemental properties?

Low Ionization Energy

e- are easily lost and it doesn't require very much energy to remove the electron.

(e- not held onto tightly because they are farther away from the nucleus)

High Ionization Energy

e- not lost easily. It takes a large amount of energy to remove an electron

(e- held onto tightly because they are held closer to the nucleus)

Trend in Ionization Energy

Decreases down a family (as atoms get bigger)

Increases across a period (as atoms get smaller)

Elements with very Negative Electron Affinities

Release a large amount of energy when they gain electrons because they really want electrons. The large negative Electron Affinity corresponds to small atoms.

Elements with only slightly negative Electron Affinities

Release only a small amount of energy when they gain an electron because they don't want the electron as much. The small negative Electron Affinity corresponds to larger atoms.

The atom with the greatest electronegativity

Flourine

The atom in the third period with the largest radius.

Sodium

The atom in the Oxygen family with the largest radius.

Po (Polonium)

The atom in the fourth period with the smallest ionization energy

Potassium (K)

The atom in the Alkaline Earth Metal Family with the smallest ionization energy.

Radium (Ra)

The most reactive Alkali Metal

Francium (Fr)

The family with the highest electronegativity and the most negative electron affinity.

Halogens

The family with the highest second Ionization energies

Alkali Metals

Elements in this family do not have measured electronegativities

Noble gases (don't bond to form molecules and have no affinity for extra electrons)

Which is larger, a chlorine atom or a chlorine ion?

Chlorine ion (because it has gained an electron)

Which is larger, a sodium atom or a sodium ion?

Sodium atom (because the ion has lost electrons)