Compounds and Molecules

1. Compounds and Molecules 4.1 vid

2. What are compounds? • Two or more elements chemically combined to form new substances.

3. What are compounds? • Chemical Bonds – the attractive forces that hold different atoms or ions together • Bonds distinguish compounds from mixtures.

4. Chemical Formula • C12H22O11 can only be sugar • H20 can only be water

5. Parts to the Formulas 2H2O Subscript Coefficient

6. Parts to the Formulas • Coefficient – gives the amount of molecules or moles • Subscript – tells the number of atoms or ions

7. Chemical Structure • Bond length -the distance between two bonded atoms • Bond angle -the angle formed between two bonded atoms

8. Models of compounds • Ball and stick model -atoms are represented balls, bonds are represented by sticks. H H BondAngle O Bond length

9. Models of compounds • Structural formulas -chemical symbols represent the atoms. H H O

10. Models of compounds • Space-filling -show the space occupied by each atom represented in the compound. Hydrogen Oxygen

11. Structure of Compounds • Network Structures = strong solids • Molecules= weak solids, liquids, or gases

12. Ionic and Covalent Bonding 4.2 fun

13. 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: • NaCl CO2 Ca2Cl • H20 KF N2

14. 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: • NaCl HCl Fe2O • CO2 KBr N2

15. Exit Ticket • 1. Go to Socrative.com • 2. Click “Student Login” and enter room# 496840 • 3. 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?

16. Why Bond? • Atoms bond so they can become stable! • They want to achieve a full outer energy level • They want 8 electrons.

17. 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

20. Ionic bond • Formed by transferring electrons • Now each ion will have 8 valence electrons NaCl Na+ + Cl-

22. Ionic bond Properties • They form network structures • high melting points • Good conductors of electricity when dissolved or melted because of their ions

24. Metallic bond • Formed by the attraction between positively charged metal ions and the electrons around them.

25. Metallic bond • Held together by free flowing electrons • Hold metallic elements together

28. Covalent Bonds • Formed when atoms share one or more valence electrons • Formed between non-metals • May form single, double, or triple bonds

31. Covalent Properties • They are poor conductors of electricity (no ions) • Low melting points. • form molecules

32. 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 (CO3)-2 Nitrate (NO3)-1

33. Fun

34. Compound Names and Formulas 4.3

35. 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+2 F- • Li+ N-3 • Al+3 S-2

36. 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

37. Writing Ionic Formulas Calcium Fluoride Step 1 - Look up both positive and negative ions Ca2+ F-1

38. Writing Ionic Compounds Step 2 Criss-cross numbers down, making subscripts Ca2+ F-1 Ca1 F2

39. Writing Ionic Compounds Step 3 Combine your new compound. Ca1 + F2 Ca1F2

40. Polyatomic ion Aluminum Carbonate • Al+3 (CO3)-2 • Al2(CO3)3 • Al2(CO3)3

41. 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

42. 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!)

43. Naming Ionic Compounds • Step one – Name the first ion in the formula Ex. CaCl2 – calcium Na2(SO4) - sodium

44. Naming Ionic Compounds • Step two – Name the second ion Ex. CaCl2 –Calcium Chloride Na2(SO4)-sodium sulfate

45. PROBLEM Ex. Fe2O3 and FeO are different compounds from different ions • Fe3+ O2- = Fe2O3 • Fe2+ O2- = FeO

46. Solution-Roman Numerals • Same naming scheme • Add a Roman Numeral to identify the charge of the metal ion.

47. Solution-Roman Numerals Fe2O3 = iron(III)Oxide FeO = iron(II)Oxide • Remember!!! • R.N. is the charge, not the subscript of the metal.

48. 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.

49. Naming Covalent Compounds • Mono – 1 • Di - 2 • Tri - 3 • Tetra - 4 • Penta - 5 • Hexa – 6 • Hepta - 7 • Octa - 8 • Nona - 9 • Deca - 10

50. Naming Covalent Compounds • Step 1 Identify the number of atoms in the first element Ex. H2O two H atoms