Midterm Part 2

32. Valence electrons and atomic numbers.

• Atomic numbers increase as you move across the periodic table

• Number of valence electrons also increase

• Transition elements are exception

33. What are the subatomic particles for an isotope.

• Ex. Carbon-12 & Carbon-14• 6 protons for each• Carbon-12– Neutrons = 6

• Carbon-14– Neutrons = 8

34. Oxidation Number

• Electrons lost or gained• See periodic table• Metals (positive) & nonmetals

(negative)

35. Fission and Fusion• Fission: when 2 nuclei separate(chain

reaction)• Fusion: when 2 nuclei come together– Ex. Sun

• Both take small masses and convert into great amounts of energy

36. Uses of nuclear applications

• Medical–Radioactive tracers –Radiation for cancer treatment

• Nuclear power plants• Nuclear weapons

37. Molecule and Atom

• Molecule: covalently bonded group of elements–Smallest part of a compound

• Atom : smallest piece of matter

38. Types of Chemical Bonds

• Ionic: metal + nonmetal• Covalent: nonmetal + nonmetal–Single, double, or triple bonds–Polyatomic ions

39. Chemical bonding and stability

• To complete outer energy level• * remember * 8 valence electrons• Exception: Hydrogen and Helium

Argon Atom

40. How does covalent bonding cause stability?

• Ex. Group 14: 4 valence electrons–Would take too much energy to lose

or gain 4 electrons –More chemically stable to just share

42. Ionic & Covalent Bonding

• Ionic Bonds (crystalline)–Metal + Nonmetal–Ex. NaF, MgO, Al2O3

• Covalent Bonds (molecular)–Nonmetal + nonmetal–*Prefixes*–Ex. P3N5 , PCl3

43. Writing chemical formulas for Binary Ionic Compounds

• Write name of positive ion first, then add –ide to end of negative ion

• Ex. KCl–Potassium Chloride

• Ex. BaF2

–Barium Fluoride

44. Balanced chemical equation

• Balance using only coefficients• Same number of atoms of each element

on each side2Mg(s) + O2 (g) 2Mgo(s)

45. Law of Conservation of Mass

Reactants = productsMatter is neither created nor destroyed.

46. Endothermic and Exothermic Reactions

• Endothermic: energy is used, temperature decreases– Ex. Cold pack

• Exothermic: energy released, temp. increases– Fire

47. Evidence of Chemical Reaction

• Evolution of gas• Precipitate formation • Changes in :–Temperature–Color–Smell

48. Synthesis Equation

A + B C

CaO(s) + H2O Ca(OH)2(aq)

49. Decomposition Equation

C A + B

NH4NO3 N2O + 2H2O

50. Single and Double Displacement Reaction

• Single DisplacementA + BC AC + BFe + CuSO4 FeSO4 + Cu

• Double DisplacementAB + CD AD + CBBa(NO3)2 + K2SO4 BaSO4 + 2KNO3

51. Reaction Rates• Affected by:–Temperature–Surface area–Add a catalyst (does not change

amount of product)

• Buoyancy (Archimede’s Principle)

• Bernoulli’s Principle• Pascal’s Principle• Heterogeneous

Mixture• Homogeneous

Mixture

• Kinetic Theory• Charles’s law• Boyle’s Law

Exam

• Group Names• Symbols (S, l, g, & aq)