TAKEN, NOT SHARED.

Bonding

• Elements bond with their valence electrons

• Types of bonds

• Ionic bond (one element takes the other’s electrons)

• Covalent bond (elements share electrons)

• In a chemical reaction, bonds break, atoms rearrange and form new bonds

COVALENT BOND• The strongest type of bond.

• Happens when electrons are shared between two atoms, making them strongly attached to one another.

“UNHAPPY ATOMS”

(Chemical Reaction)

COVALENT BOND

IONIC BOND

• The second strongest bond

• Happens between two atoms when one atom gives up an electron to another atom.

– Afterward, the atom giving up the electron has a positive charge. (subtracting a negative = adding a positive)

– Afterward, the atom taking the extra electron has a negative charge. (Adding a negative)

– The opposite charges on the atoms attract, creating the bond

IONIC BOND

Li F

WHEN BONDING HAPPENS, IT’S CALLED A CHEMICAL REACTION!

Ions (Ionic Bonding Only!)

• Ions are electrically charged atoms (+ or -)

• This happens when an electron from one atom is given to, or taken from another atom.

– Ex: NaCl when dissolved in water becomes Na+

and Cl-

– Movement of electrons and/or ions = electricity

ION-ic bond

How to spot bonds…

• Any time you see more than one element symbol side by side (no spaces), they are bonded together.

– Ex:

• H20

• NaCl

• C6H12O6

Reading Chemical Formulas

• The large number before the compound is the Coefficient.

– It tells us how many of a molecule/atom we have.

– Ex:

• 3 H20 (We have 3 H2O compounds)

• 4 H2 (We have 4 H2 molecules)

• Li (We have 1 Li atom)

• The small number after each element tells us how many atoms of a certain element is in each molecule.

– Ex:

• H2O– We have 2 hydrogen atoms in ONE water compound.

– There is no number after O, so there is only one Oxygen atom making each water compound.

• C6H12O6

– We have 6 Carbon atoms, 12 Hydrogen atoms, and 6 Oxygen atoms in ONE compound of glucose

Reading Chemical Formulas