9.18 WARM UP 1. How do elements combine to form compounds? 2. What do ionic bonds mean? 3. What do covalent bonds mean? Announcements Quiz Friday: atomic theory, atomic structure, bonding SF: 12 journal entries, data table outline, & typed hard copy of Experimental Design Learning Goal: Structure of Matter • 4 – I can describe the properties of matter and predict ways that the atoms bond • 3 – I can describe the properties of matter and identify bonds • 2 – I can describe the properties of matter • 1 – I need to review Review Atoms • Outer shell has the _________ e• The inner shells are complete and stable • Elements are organized by # of valence e• # of valence edetermines properties and how it reacts with other elements Chemical Bonds & Stability • Due to charges, atoms tend to become stable. • Atoms with full shells are stable • Atoms with 8 e- or 2 ein outer shell are stable and tend to not react with others Chemical Bonds & Stability • Atoms react to become more stable – Lose e- to get to 8 – Gain e- to get to 8 • Chemical Bond = the force of attraction that holds two atoms together as a result of the rearrangement of ebetween them • • • • • • Ionic Bonds Ionic bonds = the transfer of electrons Atoms with 5, 6, or 7 e- tend to gain Atoms with 1,2 or 3 e- tend to lose Ions = charged atoms Cation = + charge (lost e-) Anion = - charge (gained e-) Sodium & Chlorine • http://www.middleschoolchemistry.com/multimedia/chapter 4/lesson5#ionic_bond_in_sodium_chloride Properties of Ionic Bonds • Hard, brittle crystals • High melting points • Conduct electricity when dissolved in water or melted • Usually formed with a metal and nonmetal atom Atoms are lonely hearts that are constantly in search of partners to bring stability to their lives. Your job is to play matchmaker and make each atom stable by determining how many valence eeach element needs & finding a partner that will complete the valence energy level! Bachelor #1, Mr. Sodium • Mr. Sodium is very lustrous but watch out, he has an explosive personality when he gets near water or oxygen. • He is quite a lonely metal and like most metals is looking to lose a few electrons! • Since he is highly reactive, be careful who you pick to be his date! 11 Na Sodium 22 • Ms. Lithium over here is quite a catch. She’s a bit feisty , especially around water and oxygen. She, too is looking to lose electrons • Ms. Fluorine, she can light up any place! She is a non metal and is looking to gain electrons. 3 9 Li F Lithium 7 Fluorine 19 Next Contestant • Ms. Chlorine, hard to catch and rarely found on her own but she’s now looking to settle down and find someone to make her a little more stable. 17 Cl Chlorine 35 Eligible Bachelors • Sr. Potassium, also known as Mr. K, puts off• a rough side initially but calms down when paired up with a reactive mate! Mr. Barium, commonly know as the Big B, has an incredible atomic mass weighing in at 137 amu. He over time will become reactive to not only water but also air. 19 56 K Ba Potassium 39 Barium 137 Covalent Bonds • Covalent = sharing e• Usually form between atoms of nonmetals • Atom’s nucleus is the force that holds the atoms together Covalent Bonds Covalent Bonds • Water • http://www.middleschoolchemistry.com/multimedia/chapter 4/lesson4#covalent_bond_hydrogen_animation • More Covalent Bonds Methane • CH4 H C Properties of Covalent Bonds • • • • Molecular Compounds Lower melting points Lower boiling points Do not conduct electricity when dissolved in water Review Transferring e= ionic Sharing e= covalent Atomic Game • Follow the hand outs to complete the appropriate activities • You will have 8 minutes at each table, watch the clock • Table captains – in relation to the table number & your original seat number