Kinds of Chemical Bonds Unit 3

To fill their outer energy levels with electrons. Why do atoms combine? To fill their outer energy levels with electrons. To become chemically stable like the Noble Gases.

What are the 3 ways electrons move between atoms? 1.) Giving them (lose) [+] 2.) Taking them (gain) [-] 3.) Sharing them [NC]

By giving away or taking electrons, it sets up an unbalance of charges. Losing / Giving Gaining / Taking E P P E

Ion An electrically charged atom. * can be positively [+] or negatively [-] charged

Superscript Means “written above”. * tells how many electrons are unbalanced and the charge of the ion * A.K.A.: oxidation number * ex.: Ca2+ : O2- : K+ : F-

Ionic Bond The force of attraction between the opposite charges of ions. * smallest part of an ionic bond is an ION

» The Positive to Negative Attraction Ionic Bond » The Positive to Negative Attraction Na Cℓ = Na+ + Cℓ- = NaCℓ Mg S = Mg2+ + S2- = MgS

Covalent Bond The force of attraction created when atoms share electrons. * smallest part of a covalent bond is a MOLECULE

Covalent Bond Extra electrons buzz around both atoms. No electrical charge because no electrons change location permanently.

Atoms in a covalent bond do not always share the extra electrons equally. * the larger atom will be in possession of the electrons most of the time

Polar Molecule A molecule that has a positive and a negative end. * “Polar” means having opposite ends * H2O is a polar molecule

Non-Polar Molecule A molecule that does not have oppositely charged ends. * atoms share electrons equally * “Diatomic 7” = H2 N2 O2 F2 Cℓ2 Br2 I2

Most Ionic bonded compounds are crystalline solids with high melting points. * salt

Most Covalent bonded compounds are liquids or gases at room temperature. * water * carbon dioxide

You can tell the type of bond by looking at the elements in the compound. * metal + non-metal = Ionic * non-metal + non-metal = Covalent * metal + metal = Alloy [no real bond]

The End