Chemistry 6

Warm-up All elements would like to have a complete outermost energy level. Identify which Group on the periodic table are 1. Most stable 2. Least stable Explain why

Stability - Reactivity Most stable = Nobel Gasses outer electron level is full – nonreactive or INERT Least stable = Alkali Metals and Halogens missing one electron from the outer electron level

Lewis Dot Structures  Show us if an atom is stable or has a full outer shell  called an Octet (8 possible electrons)

Octet Rule Elements will LOOSE GAIN or SHARE ELECTRONS in order to ‘fill’ the valence level To complete the octet

Identify needs Go back to your Bohr Model worksheet (pg 17) Make a note for each atom How many electrons gain/loose/share needed to complete the octet

Chemical bonds Form when two or more unstable atoms combine Types of bonds tell how atoms are joined (gain/loose/share of electrons) to complete octet

Covalent Bond  Sharing electrons joins atoms with COVALENT BONDS

Ionic Bond Loosing or gaining electrons joins atoms (called ions) with IONIC BONDS

Cation Anion

Ions An atom that has gained or lost electrons Gain an electron, negative charge called an ANION Lose an electron, positive charge called a CATION

Other Bonds  Metallic (not relevant to biology)  Hydrogen (will discuss later)

Bond Practice Worksheet NameSymbolWhat is it?Dot StructureBond Sodium Chloride NaClSalt, ocean, mines ionic

Wrap up  I can explain how ionic and covalent bonds form.