Valence Electrons, Ions, and Ionic Compounds

Flashcards covering valence electrons, Bohr diagrams, ion formation, periodic table trends, and the naming and formation of ionic compounds.

Bohr Diagram

A diagram created by adding electrons from lowest to highest energy levels in concentric spheres until all electrons are placed.

Energy Levels

Concentric spheres around the nucleus where electrons exist; the first holds $2$ electrons, the second holds $8$, and the third achieves stability at $8$ electrons.

Valence Shell

The outermost energy level of an atom.

Octet Rule

The principle that atoms with full valence shells are more stable, energetically favored, and non-reactive.

Noble Gases

The group of elements that possess full valence shells ($2$, $8$, or $8$ electrons in the first three periods).

EWTLLANG

An acronym for "Everyone Wants To Look Like A Noble Gas," describing how elements gain or lose electrons to achieve a full valence shell.

Period

A horizontal row on the periodic table where all elements have the same number of energy levels.

Group

A vertical column on the periodic table where all elements have the same number of electrons in their valence shell.

Cations

Positive ($+$) ions formed when an element (typically a metal with less than $4$ valence electrons) loses electrons to achieve stability.

Anions

Negative ($-$) ions formed when an element (typically a nonmetal with greater than $4$ valence electrons) gains electrons to achieve stability.

Ionic Bonding

The process where metals lose electrons and nonmetals gain electrons to achieve full valence shells, held together by electrostatic force.

Electrostatic Force of Attraction

The force between positive and negative charges that holds an ionic compound together.

Neutrality Rule

The requirement that in an ionic compound, the total positive ($+$) charge must equal the total negative ($-$) charge, resulting in a total charge of $0$.

Criss-cross method

A shortcut for writing chemical formulas of ionic compounds by using ionic charges to determine the formula unit needed for a neutral compound.

-ide

The suffix used to change the ending of a nonmetal's name when naming an ionic compound (e.g., fluorine becomes fluoride).