COMPOUNDS AND MOLECULES 4.1 vid

WHAT ARE COMPOUNDS? Two or more elements chemically combined to form new substances.

WHAT ARE COMPOUNDS? Chemical Bonds – the attractive forces that hold different atoms or ions together Bonds distinguish compounds from mixtures.

CHEMICAL FORMULA C 12 H 22 O 11 can only be sugar H 2 0 can only be water

PARTS TO THE FORMULAS 2H2O2H2O Coefficient Subscript

PARTS TO THE FORMULAS Coefficient – gives the amount of molecules or moles Subscript – tells the number of atoms or ions

CHEMICAL STRUCTURE Bond length -the distance between two bonded atoms Bond angle -the angle formed between two bonded atoms

MODELS OF COMPOUNDS Ball and stick model -atoms are represented balls, bonds are represented by sticks. O H H Bond length Bond Angle

MODELS OF COMPOUNDS Structural formulas -chemical symbols represent the atoms. HH O

Space-filling -show the space occupied by each atom represented in the compound. Hydrogen Oxygen

STRUCTURE OF COMPOUNDS Network Structures = strong solids Molecules= weak solids, liquids, or gases

IONIC AND COVALENT BONDING 4.2 fun

OCTOBER 15, 2015 Objective: Compare and contrast ionic and covalent bonds. Do Now: Look at your definitions of ionic and covalent bonds. Then, determine which of the following compounds have ionic bonds and why you think so: NaClCO 2 Ca 2 Cl H 2 0KFN 2

OCTOBER 16, 2015 Objective: Compare and contrast ionic and covalent bonds. Do Now: Look at your definitions of ionic and covalent bonds. Then, determine which of the following compounds have ionic bonds and why you think so: NaClHClFe 2 O CO 2 KBrN 2

EXIT TICKET 1. Go to Socrative.com 2. Click “Student Login” and enter room# Then complete the Exit Ticket Question #3 Answer your teacher’s question: You are given two compounds, one is a binary ionic compound and the other is an ionic compound containing a polyatomic ions. What CLUES would you look for to identify each compound?

WHY BOND? Atoms bond so they can become stable! They want to achieve a full outer energy level They want 8 electrons.

1. IONIC BOND A bond formed by the attraction between oppositely charged ions. The joining of a positive metal ion and a negative nonmetal ion Na + + Cl - NaCl

IONIC BOND Formed by transferring electrons Now each ion will have 8 valence electrons Na + + Cl - NaCl

IONIC BOND PROPERTIES They form network structures high melting points Good conductors of electricity when dissolved or melted because of their ions

METALLIC BOND Formed by the attraction between positively charged metal ions and the electrons around them.

METALLIC BOND Held together by free flowing electrons Hold metallic elements together

COVALENT BONDS Formed when atoms share one or more valence electrons Formed between non-metals May form single, double, or triple bonds

COVALENT PROPERTIES They are poor conductors of electricity (no ions) Low melting points. form molecules

POLYATOMIC ION An ion made of two or more atoms that are covalently bonded and that act like a single ion. A molecule with a charge Examples: carbonate (CO 3 ) -2 Nitrate (NO 3 ) -1

Fun

COMPOUND NAMES AND FORMULAS 4.3

OCTOBER 19, 2015 Objective: Analyze chemical formulas and names. Write names of compounds from chemical formulas. Do Now: Pair up the following cations and anions together to form an ionic bond. Explain what criteria you used to pair them up. Cations: Anions: Ca+2F- Li+N-3 Al+3S-2

REMEMBER!!!!!!!! If it starts with metal it is an ionic compound If it starts with a nonmetal it is a covalent compound If the formula contains a parentheses (polyatomic ion) it contains both ionic and covalent bonds If it is just a metal it is metallic

WRITING IONIC FORMULAS Calcium Fluoride Step 1 - Look up both positive and negative ions Ca 2+ F -1

WRITING IONIC COMPOUNDS Step 2 Criss-cross numbers down, making subscripts Ca 2+ F -1 Ca 1 F 2

WRITING IONIC COMPOUNDS Step 3 Combine your new compound. Ca 1 + F 2  Ca 1 F 2

POLYATOMIC ION Al +3 (CO 3 ) -2 Al 2 (CO 3 ) 3 Aluminum Carbonate

OCTOBER 20, 2015 Objective: Analyze chemical formulas and names. Write names of compounds from chemical formulas. Do Now: Write the following ionic formulas: 1. Lithium oxide 2. Beryllium chloride 3. Magnesium bromide

OCTOBER 21, 2015 Objective: Analyze chemical formulas and names. Write names of compounds from chemical formulas. Block 1 – Worksheet, Binary Ionic. Do Now: Write the following formulas (you must find the charge!) ClCO 3 SO 4 H Na PO 4

NAMING IONIC COMPOUNDS Step one – Name the first ion in the formula Ex. CaCl 2 – calcium Na 2 (SO 4 ) - sodium

NAMING IONIC COMPOUNDS Step two – Name the second ion Ex. CaCl 2 –Calcium Chloride Na 2 (SO 4 )-sodium sulfate

PROBLEM Ex. Fe 2 O 3 and FeO are different compounds from different ions Fe 3+ O 2- = Fe 2 O 3 Fe 2+ O 2- = FeO

SOLUTION-ROMAN NUMERALS Same naming scheme Add a Roman Numeral to identify the charge of the metal ion.

SOLUTION-ROMAN NUMERALS Fe 2 O 3 = iron(III)Oxide FeO = iron(II)Oxide Remember!!!  R.N. is the charge, not the subscript of the metal.

OCTOBER 22, 2015 Objective: Apply knowledge of ionic and covalent bonds to identify unknowns in a laboratory experiment. Do Now: List 3 properties each of ionic and covalent bonds.

NAMING COVALENT COMPOUNDS Mono – 1 Di - 2 Tri - 3 Tetra - 4 Penta - 5 Hexa – 6 Hepta - 7 Octa - 8 Nona - 9 Deca - 10

NAMING COVALENT COMPOUNDS Step 1 Identify the number of atoms in the first element Ex. H 2 Otwo H atoms

NAMING COVALENT COMPOUNDS Step 2 Identify the number of atoms in the 2 nd element. Ex. H 2 Oone O atom

NAMING COVALENT COMPOUNDS Step 3 Name the compound with the appropriate prefixes. Ex. H 2 O dihydrogen monoxygen

NAMING COVALENT COMPOUNDS Step 4 add an -ide ending to the second element Ex. Dihydrogen monoxide

EMPIRICAL FORMULA The simplest chemical formula of a compound. Different covalent compounds can have same empirical formula