Unit 7: Ionic Bonds

Chemical bond

Force that holds two atoms together

Covalent bond

Attraction between nucleus (+) and electrons (-)

Octet rule

The tendency of atoms to prefer to have eight electrons in the outermost energy level (valence shell)

Ion

Atoms or groups of atoms with a positive or negative charge

Cation

• Positive-charged ion

• Formed when an atom loses a valence electron

Anion

• Negative-charged ion

• Formed when an atom gains a valence electron

Groups _,_,_, will lose valence e^- to have noble gas configurations

1, 2, 3

Groups _,_,_, will gain valence e^- to fill energy level

15, 16, 17

Ionic bond

Electrostatic force that holds oppositely charged particles together

Monatomic ions

Ions formed from a single atom

Oxidation number

The charge of an atom

Polyatomic ions

Ions made up of more than one atom

Almost all polyatomic ions are ____ with the only exception being ammonium

Negative

Crystal lattice

Strong attraction of ions results in three-dimensional geometric arrangements

Endothermic reaction

Chemical reaction that absorbs energy

Exothermic reaction

Chemical reaction that releases energy

Energy of formation of ionic compounds is always _______

Exothermic

Lattice energy

Energy needed to separate ions of an ionic compound

Sea of Electrons

A model where valence electrons are delocalized and are free to move

Metallic bond

The attraction of a metallic cation for delocalized electrons

Malleable

The ability of a metal to be easily hammered into sheets

Ductile

A metal’s ability to easily be pulled into wire

Alloy

A mixture of elements that has metallic properties

Transition metals are even better at conducting heat and electricity because of _ orbital electrons

d