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Physical Science EOC Review. Marilyn Pendley, Instructor, CCCMC Modified by R. Kittrell Jan 2015 & 5Jan2016. Scientific Experimentation controlled experiment -Only one variable should be changed at a time. Manipulated (independent) variable – changed by the experimenter.
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Physical Science EOC Review Marilyn Pendley, Instructor, CCCMC Modified by R. Kittrell Jan 2015 & 5Jan2016
Scientific Experimentation controlled experiment -Only one variable should be changed at a time. Manipulated (independent) variable – changed by the experimenter. Responding (dependent) variable – the effect that is measured.
Law vs. Theory • Develop a law • Law: Summarizes the outcome of several experiments that occur repeatedly and consistently. • Example: The spoiled food served at lunch makes people sick with a stomachache. • Develop a theory • Theory: Explanation for why a law exists. • Example: It is the bacteria in the spoiled food that makes people ill.
Types of Measurements 1. Length a. The distance from one point to another point. b. Base unit is the meter (m). c. Tool is the metric ruler. 2. Volume a. The amount of space a substance occupies. b. Base unit is the liter (L). c. Tools: metric ruler for regular solids or graduated cylinder for liquids.
3. Mass a. The amount of matter in a substance. b. Base unit - kilogram (kg). c. Tool is the balance. 4. Weight a. A measure of gravitational force on an object. b. Unit is the newton (N). c. Tool is the scale.
5. Time a. How long an event takes to occur. b. Unit is the second (s). c. Tool is the clock (stopwatch). 6. Temperature a. The amount of kinetic energy a substance has. b. SI unit is the Kelvin (K). c. Tool is the thermometer.
7. Density a. How compacted the matter is in a substance. b. Units can be g/mL, g/cm3, kg/m3. c. Density is a derived unit (it is made up of other types of measurement). d. D = m / v e. Objects float if their density is less than the density of the fluid they are in.
Thomson’s Experiment: • In Thomson’s model of the atom, the negative charges arescattered throughout an atom filled with a positivelycharged mass of matter. • The “plum pudding” model
What did this experiment prove? Beam of Alpha-Particles were REPELED by Positive Charges in the nucleus
Atomic Theory:Who’s Model of the Atom? Neils Bohr The Bohr Model
Electron Cloud An _________ _______ is a visual model of the most likely locations for electrons in an atom. www.unitedstreaming.com – Physical Science – Elements, Compounds, and Atoms An Orbital is a region of space around the nucleus where an electron is likely to be found. * An electron cloud is a good approximation of how electrons behave in their orbitals.
Lewis Dot Diagram • An electron dot diagram uses the symbol of the element and dots to represent the outer level electrons. • Electron dot diagramsare used also to show how the electrons in the outer energy level are bonded when elements combine to form compounds.
Atom the smallest particle making up elements Proton = + Neutron = neutral Electron = -
Atomic Structure Basics: • Protons: positively charged particles, weighing 1 atomic mass unit (1.67x10-24 grams) and located in the nucleus. • Neutrons: neutrally charged particles, weighing approximately 1 atomic mass unit and located in the nucleus. • Electrons: negatively charged particles , weighing zero atomic mass units, located in orbitals of the energy levels found outside the atomic nucleus
Atomic Number: • The number of protons in an atom determines what element it is. • Add or subtract even one proton from an atom of any element and you no longer have the original element in any form. Now you have a different element! • Play the Name the Atom Game at: • http://www.learner.org/interactives/periodic/basics_interactive.html
6 Atomic # C 12.011 Atomic Mass Drawing an Atom of Carbon = # of p+ and # of e- Carbon has 6 p+ and 6 e- minus Atomic # = # of n0 Carbon has 6 n0
e- e- 6 p+ 6 n0 e- e- e- e- Drawing an Atom of Carbon
Periodic Table Basics: Essential Question: What are Horizontal Rows called? Answer: PERIODS
Electron Configuration • The “Period” number is equal to the number of energy levels in an atom • Remember: The number of electrons are equal to the number of protons in a neutral atom
What are Groups on the Periodic Table? Essential Question: Groups are also known as Families of Elements. They share chemical properties. WHY? Answer: They have the same number of outer shell electrons.
Electron Configuration • For Groups IA – VIII the group numbers are equal to the number of outer shell electrons or valence electrons • Group “IA” has ONE valence electron • Group “IIA” has TWO valence electrons; etc.
Name that GROUP: The Alkali Metals IA = one outer shell electrons therefore Oxidation state? +1
Name that GROUP: The Alkali Earth Metals IIA = two outer shell electrons Oxidation state? +2
Name that GROUP: The Noble Gases VIIIA = eight outer shell electrons (except Helium which has 2 but is FULL) therefore Oxidation state? NOT!
Name that GROUP: The HALOGENS The Salt Formers VIIA = SEVEN outer shell electrons therefore Oxidation state? -1
Name that GROUP: The Transition Metals B series = usually 2 or 3 outer shell electrons therefore Oxidation state? +2 or +3
Criss-Cross Method • Determine the charges/oxidation #’s for each element. • By criss-crossing the charges of the elements you can easily write the chemical formula • Example: Hydrogen + Oxygen • H + O IONS = H+1 + O–2 • Criss cross the oxidation # • just the numbers - not the + / - signs • Write the numbers as subscripts • bottom right of symbol
Criss Cross Method This becomes H+1 O-2 CrissCross the numbers H2O1 Final: H2O • Where is the 1 in the final formula?
Criss-Cross Method e- This becomes H+1 O-2 CrissCross the numbers H2O1 Final: H2O • Where is the 1 in the final formula? e-
Criss-Cross Method - -You Try it! Mg + O Ca + P K + S C + H As + S C + O
Criss-Cross MethodYou Try • Mg + O • Ca + P • K + S • C + H • As + S • C + O Mg2O2 MgO Ca3P2 Just like with Fractions in math the Numbers will reduce! K2S CH4 As2S3 C2H4 CO2
Criss-Cross & Polyatomic Ions • Sodium + Sulfate • Na + SO4 • Na+1 + (SO4)-2 Do the Criss-Cross Na2(SO4)1 Final: Na2(SO4)
Chemical Bonding: • Three types of bonding • Ionic Ionic Bonding • Covalent • Metallic Game: Bonding Animations and short clips AWESOME MOVIE ON BONDING 30 minutes long
Ionic Bonding • Ionic Bonds: between oppositely charged atoms; usually on opposite sides of the periodic table (nonmetal and a metal) • transfer electrons • form networks, not molecules • conduct electricity
Covalent Bonds • Covalent Bonds: share electrons; usually between 2 elements close on the periodic table (2 nonmetals) • nonpolar covalent bond: e- shared equally • polar covalent bond: e- shared unequally
Metallic Bonding • “sea of electrons”: electrons can “float” freely between atoms; allows metals to conduct electricity well
Rules for naming andwriting chemical formulas 1. Metal name comes first 2. Change the ending of the second element to “ide” • If you have two nonmetals, use the prefixes: Mono – 1 Penta - 5 Di - 2 Hexa - 6 Tri - 3 Hepta - 7 Tetra – 4 Octa - 8
Which of the following is the correct name of a combination of sodium and iodine? • a) sodium chloride • b) sodium iodide • c) sodium iodine • d) iodine sodium
Transition Metal Naming • Transition metals show their charges as Roman Numerals because they can change charge!! FeO = Fe+2 + O-2 Iron (II) Oxide Fe2O3 = Fe+3 + O-2 Iron (III) Oxide
Chemical Reactions Types • Combustion: ALWAYS has O2 as a REACTANT! • AB + O2 AO + BO • Single-Replacement (single-displacement): • AX + B A + BX • Double-Replacement (double-displacement): • AX + BY AY + BX
Types of Chemical Reactions. Two or more elements or compounds combine to make a more complex substance A + B → AB Compounds break down into simpler substances AB → A + B Occurs when one element replaces another one in a compound AB + C → AC + B Occurs when different atoms in two different compounds trade places AB + CD → AC + BD A = Red B = Blue C = Green D = Yellow
Identifying Chemical Reactions Use colored pencils to circle the common atoms or compounds in each equation to help you determine the type of reaction it illustrates. Use the code below to classify each reaction. S = Synthesis SR = Single Replacement D = Decomposition DR = Double Replacement ____ P + O2 → P4O10 ____ Mg + O2 → MgO ____ HgO → Hg + O2 ____ Al2O3 → Al + O2 ____ Cl2 + NaBr → NaCl + Br2 ____ H2 + N2 → NH3
____ Na + Br2 → NaBr ____ CuCl2 + H2S → CuS + HCl ____ HgO + Cl2 → HgCl + O2 ____ C + H2 → CH4 ____ KClO3 → KCl + O2 ____ S8 + F2 → SF6 ____ BaCl2 + Na2 SO4 → NaCl + BaSO4
- - + + Acids & Bases • The strength of an acid or base depends on how many acid or base particles dissociate into ions in water. • Strong Acid/Base • 100% ions in water • strong electrolyte • HCl, HNO3, NaOH, LiOH • Weak Acid/Base • few ions in water • weak electrolyte • HC2H3O2, NH3
pH Scale • pH • a measure of the concentration of H3O+ ions in solution • measured with a pH meter or an indicator with a wide color range
Atomic Structure: How many neutrons in the following isotopes? Hydrogen – 1 Helium – 4 Lithium – 6 Sodium – 22
A X Mass Number Element Symbol Z Atomic Number 1 3 2 H (D) H (T) H 1 1 1 235 238 U U 92 92 More Isotope stuff…