Presentation on theme: "Bellringer Draw a model for the following elements: A. Sodium"— Presentation transcript:
1 Bellringer Draw a model for the following elements: A. Sodium B. Chlorine2. How many valence electrons does sodium have?3. If sodium lost its valence electrons, what would its charge be?4. How many valence electrons does chlorine have?5. If chlorine gained an electron, what would its charge be?
2 Sodium Chlorine 1 A. 1 B. X X X X X X X X X X X X X X X X X X X X X X P: 11N: 12XXXP: 17N: 18XXXXXXXXXXXOne+1Seven-1
3 I. Bonding AtomsAtoms bond because their valence electrons interactBonding occurs so that atoms will have stable outer energy levelsWhat is a stable outer energy level? How many electrons?1st Energy level: 2e-ii. 2nd, 3rd, 4th, etc…Energy level: 8e-
4 Example: HydrogenValence electrons: 1Energy levels: 1XXThe valence electron in each hydrogen is shared, giving each atom a stable outer energy level.
5 II. Ionic BondsIonic Bonds –Formed between oppositely charged ionsMetals form positive ions2. Nonmetals form negative ionsB. When one atom loses an electron, another atom gains that same electronSalt is formed from positively charged sodium ions and negatively charged chlorine ions
6 Chloride Ion (negative) Example:Sodium Ion (positive)Na [Na]+Cl [ Cl ]-Chloride Ion (negative)
7 C. The chemical formula, NaCl, tells the ratio of sodium to chloride ions D. Characteristics of ionic compounds:Conduct electricity when dissolvedMetallic bonds – the attraction between a nucleus of one atom and the electrons from another atomCauses atoms to pack close to each other
8 III. Covalent BondsCovalent Bond –Molecules, made when electrons are shared between atoms
9 The line indicates shared electrons Example: ChlorineSeven Valence ElectronsXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXThe line indicates shared electronsCl Cl
10 O O N N Elements can form double or triple bonds The compounds above share electrons equally, so they form nonpolar covalent bonds2. Not all covalent bonds are nonpolarWater is a polar covalent molecule
11 IV. Polyatomic IonsPolyatomic Ions –Groups of covalently bonded atoms that have either gained or lost electronsPolyatomic Ion Examples:NH4+ammoniumPO33-phosphiteNO2-nitriteNO3-nitrateOH-hydroxide
12 C. Polyatomic ions usually end in -ate or -ite B. A polyatomic ion that is bonded with another atom is often indicated with parentheses(NH4)2SO4Ammonium sulfateBut not alwaysNH4NO3Ammonium nitrateC. Polyatomic ions usually end in -ate or -ite-ate indicates one additional oxygen atom than the polyatomic ion with -iteClO3-chlorateClO2-chlorite
13 Quiz: Match the polyatomic ion with its name ____ 1. SO42-BA. sulfite____ 2. SO32-AB. sulfate_____ 3. AsO43-CC. arsenate____ 4. AsO33-DD. arsenite