Chemical Bonding

Chemical BondA force that holds two or more

atoms together◦This happens because atoms prefer

to have a full outer shell◦Atoms can share, lose, or gain

valence electrons

Atoms want to be STABLEAtoms are stable when their outer

most energy level is fullUnstable atoms have spaces in

their outer energy level◦All atoms are unstable alone except

for which group? Noble Gases

Because most are unstable alone, they combine with others to become stable

How do atoms Bond?Ionic bondsCovalent bonds

By using Lewis Dot DiagramsOnly concerned with valence

electrons!!

How will we represent bonds?

QuestionWhich electrons are we

concerned with during bonding?

Lewis Dot Diagram RefresherDraw the diagram for:

◦Beryllium◦Aluminum◦Tin◦Bismuth◦Radon

Ionic BondsWhen atoms become stable by either

giving or taking electrons from another atom◦Most often a metal and a non-metal bond

Neutral atom- if # of protons and # of electrons are equal

Ion- an atom that has gained or lost electrons◦ Ions have electrical charges

QuestionMost of the atoms on the periodic

table are neutral. (T/F)Most of the time, which two types

of elements are bonding together in an ionic bond?(metal and non-metal/ non-metal and non-metal/ metal and metal)

IonsCation- an atom that loses

electrons◦Have positive charges◦Na+

Anion- an atom that gains electrons◦Have negative charges◦Cl-

Opposites Attract!!◦Atoms with opposite charges bond

together

QuestionWhat is an ion?O ++ is an example of

(anion/cation)

How/why do ionic bonds form?

Covalent BondsWhen two atoms share their

outer energy level by sharing a pair of electrons◦Most often a non-metal and a non-

metal bond

Both atoms keep their valence electrons

Charges don’t change, but they become stable