Name Period Date Physical Science 2nd Semester Final Exam Study Guide (2012-2013) 1. Physical Science Basics a. What tool(s) would you want to use to find the: i. Mass of an object? triple beam balance Basic SI Unit? kg ii. Volume of an object? ruler or water displacement method Basic SI Unit? cm³ or ml iii. Length of an object? Ruler Basic SI Unit? meter iv. Density of an object? graduated cylinder Basic SI Unit? ml b. What is the formula for calculating density? mass/volume i. What is the density of a cube that is 15 g and has a volume of 3 cm 3? 5g/cm³ ii. Compare the density of solid H 2 O to liquid H 2 O, and explain what observable effect this has. solid H 2 Ois less dense than liquid H 2 O 2. Chemistry Basics a. Element (def.) substance made up of one kind of atom b. Atom (def.) basic building block of matter c. Compound (def.) a molecule that contains atoms or molecules of two or more different elements d. Molecule (def.) a combination of two or more of the same or different atoms that are bonded together 3. Model of the Atom: Evolution of the Atomic Theory Atoms are so small that many scientists throughout history have created models to describe them. Why have atomic theories changed over time? Better technology came around. Scientist Year Major Discovery/ Contribution Name of atomic model John Dalton 1802 Each element is made up of small, indivisible particles called atoms. Different elements have atoms of different masses. Billiard Ball Model J.J. Thomson 1897 Negatively charged electron Plum Pudding Model Niels Bohr Ernest Rutherford 4. Periodic Table 1913 Electrons move fixed orbits around the atom s nucleus in specific layers, or electron shells; Atoms absorb or give off energy when the electrons move from one shell (energy level) to another 1909 1909 (Based on idea that positive reflects positive) atom mostly empty space; electrons orbit randomly around positively charged nucleus Bohr Model Planetary Model a. The current periodic table is arranged by increasing atomic number. b. Reading the Periodic Table i. An element s properties can be predicted from its location in the periodic table. ii. The atomic number represents the number of protons. iii. The atomic mass represents the number of neutrons and protons. 1
iv. The atomic symbol represents the name of the element. v. The group/family number represents how many valence electrons it has. vi. The row/period number represents how many shells it has. vii. This group contains the most elements: metals. c. Matching Word Bank: Metalloid, transition element, metal, non-metal, group 18- noble gases, group, group 1 The most stable elements are found here. They are colorless tasteless gases that glow when an electrical current passes through them. Elements that share some properties with metals, and some with non-metals. Group 18-Noble Gases Metalloid Column of elements in the periodic table that have similar physical or chemical properties. Group The most reactive elements in the periodic table, and are soft enough to be cut with a knife. Group 1 An element that has a shiny luster, is a good conductor of heat and electricity, is malleable and ductile. Elements in groups 3-12 Element that is usually a gas or brittle, solid at room temperature, and does not conduct heat and electricity well. 5. Parts of an Atom Metal Transition Elements Non-Metals Krypton is located in group 18. It has 8 valence electrons, which is the most that any element can have. Krypton s atomic number is 36 and its atomic mass is 84. It has 36 protons, 18 neutrons, and 36 electrons. 6. Properties of Atoms Gaining or Losing Electrons a. An atom that has gained or lost an electron is called a(n) ion. b. Group (# and name) Group 1/Alkali Metals lose electrons most easily. c. Group (# and name) Group 17/Halogens gains electrons most easily. i. Elements in group 17 want to bond with elements in group 1. ii. Elements in group 16 want to bond with elements in group 2. d. The charge becomes positive when what has happened? When an atom has lost an electron. i. What do we call a positively charged ion? Cation. e. The charge becomes negative when what has happened? When an atom gains and electron. i. What do we call a negatively charged ion? Anion. f. An ionic bond is an attraction between what charges? Positive and Negative. 7. DNA Subatomic Particle a. True / False. All things, living and non-living are made up of atoms. True Charge Location in the atom Proton + In the Nucleus Electron - Electron Cloud or Valence Shell Neutron Neutral In the Nucleus Nucleus Positive Middle The atom shown to the left has 7 valence electrons. This atom has 7 electrons that would be involved in bonding. 2
b. Macromolecule (def.) A molecule containing a lot of atoms (100). c. List the 5 elements that make up the DNA macromolecule: 1). Carbon; 2). Hydrogen; 3).Oxygen; 4). Nitrogen; 5). Phosphorous. 8. Chemical Bonding a. Ionic bond i. Metal / non-metal and metal / non-metal bonded together ii. Protons / neutrons / electrons are shared / transferred iii. Draw how Aluminum and Oxygen would ionically bond (using arrows). b. Covalent bond i. Metal / non-metal and metal / non-metal bonded together ii. Protons / neutrons / electrons are shared / transferred iii. Draw the structural and Lewis structure for Carbon tetrachloride. c. Classify the following compounds as ionic or covalent, then name them accordingly: i. KCl Potassium and Chlorine Ionic Bond ii. CO 2 Carbon and Oxygen Covalent Bond iii. CaF 2 Calcium and Fluorine Ionic Bond iv. P 2 O 5 Phosphorous and Oxygen Covalent Bond 9. Naming Chemical Formulas a. H 2 O is the molecular formula for water. The 2 means 2 hydrogen atoms; no number after the O indicates 1 oxygen atom. b. The molecular formula for oxygen gas is O 2. i. Oxygen is a diatomic molecule because it has 2 oxygen atoms. c. C 6 H 12 O 6 is the chemical formula for Glucose. d. The chemical formula for methane is CH 4. 10. Physical and Chemical Properties and Changes a. Identify the following as either being a physical property or a chemical property: i. Flammability Chemical ii. Melting point Physical iii. Color Physical b. Name a property that would describe salt. white ; Name a property that would identify salt taste c. A chemical / physical change occurs when bonds are broken. d. A chemical / physical change occurs when no new substance is formed. e. Physical change (def.) A change that alters the form or appearance, but does not change the substance. i. Name 3 examples of a physical change: 1. Ice Melting 2. Chopping Wood 3. Painting a Car f. Chemical change (def.) A change in matter that produces a new substance. i. Name examples of a chemical change: 1. A Burning Tree 2. Cookies 3. Rusting ii. Name 3 signs that a chemical change has occurred: 1. Bubbles of Gas 2.A Change in Volume 3. Light is Emitted g. Balancing Chemical Equations i. 2 H 2 + O 2 2H 2 O 3
h. How does the Law of Conservation of Mass apply to the equation you balanced above? Matter can neither be created nor destroyed, but can be changed in form. i. What forms of energy could be transferred in a chemical reaction? Heat Light i. A change that gives off energy is called Exothermic Ex. Fireworks ii. A change that absorbs energy is called Endothermic Ex. Cold Pack iii. True / False. Every chemical reaction involves a change in energy. 11. Mixtures a. Heterogeneous (def.) A Non-Uniform Mixture i. Name an example of a heterogeneous mixture: A Salad. b. Homogeneous (def.) A Mixture in which the properties are uniform. i. Name an example of a homogeneous mixture: Hot Tea. c. Separating Mixtures: Name & give a brief description of the 5 physical methods to separate mixtures: 1. Magnetism Separates objects with magnetic properties from objects with non-magnetic properties. 2. Filtration Separates a solid from a liquid. 3. Dissolving Separates a liquid from a solid. 4. Evaporation Separates a dissolved SOLUTE from a SOLUTION. 5. Chromatography Separates the different colors in dyes. d. Solutions i. Solute (def.) is dissolved ii. Solvent (def.) does the dissolving iii. Solubility (def.) How much of a substance will dissolve in a liquid. iv. In Kool-Aid, identify the solute Sugar or the Mix and the solvent Water v. True / False. Typically there is more solute than solvent in a solution. vi. True / False. Solutes and solvents can be solids, liquids, or gases. vii. True / False. When a salt dissolves in water, each of its particles is surrounded by water molecules. This is why the freezing point of salt water is lower than the freezing point of fresh water. 12. Acids and Bases a. Acidic solutions ph levels from 0 to 6.9 ; Taste Sour; Ex. Citrus Fruit i. What can a substance do if it has a warning of corrosive? Eat through materials. b. Basic solutions ph levels from 7.1 to 14; Taste Bitter; Ex. Ammonia 13. Phase Changes a. The three main states of matter are: Solid Liquid Gas b. Draw the molecular arrangement of each: o o o o ooooooooooo o o o o o o o o o o o o o o o o o o c. Label the Phase Change Diagram. Use arrows where necessary (phase transitions). See Below Solid A Liquid C Gas E Solid and Liquid B Liquid and Gas D Freezing B Melting B Evaporating D Condensing D 4
d. The average kinetic energy of the particles of a substance going through a phase transition can be described as (circle all that apply): increasing / decreasing / staying the same. e. Compare the amount of kinetic energy (motion) of the particles in a solid to a gas. A solid has less kinetic energy. 14. Types of Energy a. Energy (def.) The Ability to do Work. b. What does it mean if something has potential energy? Capable of doing work. i. Example: Roller coaster as it is getting ready to take off. c. When does an object possess kinetic energy? As it s moving. i. Example: Roller Coaster. d. Chemical PE (def.) Capable of transferring chemical energy. i. Example: Plants using photosynthesis to make food. 15. Energy Transformations i. The law of conservation of energy states that when one form of energy is converted into another, Energy cannot be created or destroyed, only transformed from one type to another ii. True / False. Most forms of energy cannot be converted into other forms. b. Natural gas (Chemical energy) heats (Thermal energy) water. c. Batteries (Chemical energy) are used to turn on a flashlight (Electromagnetic energy). d. You rub your hands together (Thermal energy) on a cold day and friction is created to produce heat (Thermal energy). e. A microwave (Electromagnetic energy) in a house turns on because of energy produced in a nuclear power plant from an atom s nucleus ( nuclear energy)? f. A light bulb [visible light] (Electromagnetic energy) turns on because of turning on the light switch (Kinetic energy)? g. Fossil fuels (Chemical energy) are burned, which is called combustion, and heat (Thermal energy) is released. h. A spinning turbine (Mechanical energy) produces usable energy to power homes ( electrical energy). 16. Sources of Energy a. Identify the following as being renewable or non-renewable: i. Biomass Renewable v. Solar Renewable ii. Coal Non-Renewable vi. Nuclear Non-Renewable iii. Petroleum Non-Renewable vii. Hydroelectric Renewable iv. Wind Renewable viii. Geothermal Renewable b. What part of the water cycle would not be possible without solar energy? Evaporation c. Nuclear Energy i. Energy stored in an Atom s Nucleus. ii. Nuclear Fission (def.) When a nucleus splits. iii. Nuclear Fusion (def.) When nuclei fuse together. iv. True / False. Fusion releases 3-4 times more energy than fission. v. True / False. Only nuclear energy is produced in a nuclear reaction, not light or heat. 17. Heat Transfer a. Conduction (def.) the transfer of heat energy between substances that are touching i. Example: molecule to molecule 5
b. Convection (def.) the cyclical motion of molecules in a gas or liquid caused by the transfer of heat through a surface. i. Example: Hot Air Balloon. c. Radiation (def.) Electromagnetic waves travel through space and transfer heat energy. i. Example: Microwave. d. Temperature (def.) The measure of the amount of kinetic energy in a substance. i. The scale to measure the amount of KE in the atoms of a substance: Celsius. e. Heat (def.) is the transfer of energy from an object with high molecular K.E., to an object with low molecular K.E. i. Heat moves from a hotter object to a cooler object. f. Insulator (def.) A substance that prevents or slows the flow of heat energy. i. Example: Rubber. g. Conductor (def.) substances that allow electrons to move freely across the surface of their atoms i. Example: Metals 18. Electricity a. Static Electricity (def.) Build up of charges on an object. b. Static Discharge (def.)spark or shock; the loss of static electricity as electric charges move off an object in an attempt to become neutrally charged. c. A switch turns a circuit on and off by opening or closing. d. Series circuits have one path, while Parallel circuits have more than one path. e. Circuits A & C are Series. f. Circuits B & E are Parallel. g. Electric currents always flow from the: Negative to the Positive. h. In a series circuit: finish the saying when one light bulb goes out they all go out i. In a series circuit: Adding another bulb will add resistance and make the light dimmer j. True / False. In a parallel circuit, the current from each bulb has its own path. k. An electric current will always follow the path of least resistance. 19. Magnetism a. Magnetism (def.) the force of attraction or repulsion of magnetic material. b. Magnetism in a physical / chemical property. c. Poles that attract are different; Poles that repel are the same. d. The region around the magnet is known as the Magnetic Field. The closer these lines are together, the stronger the magnetic field. e. True / False. A magnet is capable of producing an electric current. 6