Name _______________________________________________ Period __________ Date ______________ Test Date: ________________ Chemistry Unit Test Study Guide (2012-2013) 1. Chemistry Basics a. b. c. d. e. Atom (def.) ___________________________________________________________________________________________ Element (def.) _________________________________________________________________________ Ex. ____________ Compound (def.) ________________________________________________________________________Ex. ____________ Molecule (def.) _________________________________________________________________________ Ex. ____________ Mixture (def.) __________________________________________________________________________ Ex. ____________ 2. Periodic Table a. b. c. This person developed the first useful periodic table: _____________________________________. Properties Elements are arranged by increasing ____________________. The atomic mass of an element is determined by _______________________________________. The atomic number of an element represents ________________________________________. Metals are found on the left / right side of the staircase on the periodic table. Nonmetals are found on the left / right side of the staircase on the periodic table. The majority of the elements on the periodic table are metals / non-metals. Elements in the same group or family (column) have similar physical and chemical properties based on the number of _________________ in their _______________ shell. Matching Section: 1) Elements that share some properties with metals, and some with non-metals. 2) Column of elements in the periodic table that have similar physical or chemical properties. 3) An element that has a shiny luster, is a good conductor of heat and electricity, is malleable and ductile. A) Halogens B) Metal C) Noble Gases 4) Elements in groups 3-12, like gold and silver. 5) Element that is usually a gas or brittle, solid at room temperature, and does not conduct heat and electricity well. 6) Group 17 elements, such as F, Cl, and Br are known as this. 7) The most reactive elements in the periodic table are found in this group. 8) Elements in this group do not form compounds. D) Metalloid E) Transition Element F) Group 1 G) Non-metal H) Group 2 3. Acids and Bases a. b. c. d. e. f. The pH of a substance can be determined using ____________________ paper Neutral substances have a pH of __________. An example of a common neutral substance is ____________. Acids- Name 3 properties (ex: feel, taste, uses, etc.): 1. _______________ 2. _______________ 3. _____________ a. pH range for acids: ____________ Bases- Name 3 properties (ex: feel, taste, uses, etc.): 1. _______________ 2. _______________ 3. _____________ a. pH range for bases: ____________ True / False. Strong Acids and Strong Bases are both corrosive, which means they eat away at body tissue and dissolve other objects, and should always be handled with care. Interpreting a pH scale diagram: a. Identify the strongest acid shown on the pH scale below: __________________ b. Identify the strongest base shown on the pH scale below: __________________ c. Identify the weakest acid shown on the pH scale below: __________________ d. Identify the weakest base shown on the pH scale below: __________________ e. Identify the neutral substance shown on the pH scale below: __________________ Stomach acid lemon grapes tomatoes bananas milk water eggs baking soda soap ammonia bleach oven cleaner 1 4. Mixtures a. b. c. d. e. Mixture (def.) ________________________________________________________ Heterogeneous (def.) ___________________________________________________ Give 3 examples of a heterogeneous mixture: 1. ________________ 2. _________________ 3. ________________ Homogeneous (def.) ____________________________________________________ Give 3 examples of a homogeneous mixture: 1. _________________ 2. _________________ 3. ________________ Separating Mixtures Name & give a brief description of the 4 ways that a mixture can be separated (some of which we did in class!) 1. _________________________________________________________________________________ 2. _________________________________________________________________________________ 3. _________________________________________________________________________________ 4. _________________________________________________________________________________ Solutions Solute (def.) ____________________________________________________________________________ Solvent (def.) ___________________________________________________________________________ Solubility (def.) __________________________________________________________________________ In Kool-Aid, identify the solute: ___________________ and the solvent: _______________ TRUE / FALSE. When a solid dissolves in water, each particle becomes surrounded by water molecules. 5. Model of the Atom: Evolution of the Atomic Theory Atoms are so small that scientists create models to describe them. Complete the table below for each of the scientists that have contributed to the evolution of the atomic model. Scientist Discovery Name of atomic model Year 1 2 3 4 5 6 6. Parts of an Atom a. Shown below is the Bohr model of the atom, proposed by scientist Niels Bohr. Scientists create models to describe atoms, because __________________________________. Subatomic Mass Location in the Charge Particle (in amu) atom Proton Electron Neutron Nucleus The atom is made up of mostly ___________ ____________. d. e. f. b. The greatest number of valence electrons an atom can have is ______. c. The majority of the mass of an atom is found ____________________. This atom has ______ valence electrons, and has _______ electrons that would be involved in bonding. In an atom which has an equal number of protons and electrons, the atom’s charge would be _______________. An atom is made up of mostly ______________ space. 2 7. Properties of Atoms Fill in the blanks for the elements in this chart. When completing this chart, round all atomic masses to the nearest whole number. Reminder: Atomic mass = # of ____________ + # of ______________; Atomic number = # of ________________ Element Atomic Symbol Group # # of Valence Electrons # of protons # of neutrons # of electrons Atomic mass # Atomic number Sodium Carbon Oxygen Phosphorus Hydrogen Nitrogen Chlorine 8. Gaining or Losing Electrons a. b. c. d. e. f. g. An atom that has gained or lost an electron is called a(n) _________________________ What is a cation? ____________________________________ What is an anion? ____________________________________ The charge becomes positive when what has happened? ___________________________________________________________________ The charge becomes negative when what has happened? ___________________________________________________________________ If an atom in group 16 gains 2 electrons, how many valence electrons will it have? _______ What will its charge be? _______ What charges attract to each other? _______________________________________ 9. Bonding Circle the word that makes each of the sentences below correct. a. Atoms are held together in molecules by physical / chemical bonds. b. Which electrons (name and location) are involved in chemical bonding? __________________________________________ c. Ionic bonds: Metal/non-metal OR non-metal/non-metal bond together in ionic bonds and electrons are shared / transferred. d. Covalent bonds Metal/non-metal OR non-metal/non-metal bond together in covalent bonds and electrons are shared / transferred. e. Classify the following compounds as ionic or covalent: KCl _________________ CO2 _________________ NaCl ________________ CH4 _________________ f. Molecules such as H2, N2, O2, and Cl2 are called ______________ molecules. g. Draw the following molecules: i) Nitrogen triiodide Formula: _________ (Lewis Structure) (Structural Formula) ii) Mg3N2 Name: _____________________ (Use arrows to draw how Magnesium and Nitrogen ionically bond.) 10. Naming Chemical Formulas a. Naming Covalent Molecules Prefixes: 1 atom-_______; 2 atoms-_____; 3 atoms______; 4 atoms-_______; 5 atoms-_______; 6 atoms-_______ 3 Write names for the following covalent chemical formulas: HBr _____________________ SCl4 _____________________ N2O4 ___________________ SO3 ____________________ b. Naming Ionic Molecules What is written first? Positive ion (cation) / negative ion (anion) The 2nd word is the first syllable of the 2nd, with the suffix (ending) _________. Ionic compounds use prefixes like mono-, di-, and tri-. True / False NaCl _________________________ Li2O _________________________ CaF2 _________________________ MgO _________________________ Pb3N4 _________________________ Mn(CO3)2 _________________________ c. Common Names of Molecules- Complete the chart! Formula Chemical Name Common Name C6H12O6 Dihydrogen monoxide Table Salt Carbon dioxide Carbon dioxide Table Sugar 11. Physical and Chemical Changes a. c. The Law of Conservation of Mass states that: _______________________________________________________________ Physical change (def.) ___________________________________________________________________________________ List 3 pieces of evidence that a physical change has occurred: ___________________________________________ Chemical change (def.) __________________________________________________________________________________ List 9 pieces of evidence that a chemical change has occurred: __________________________________________ _____________________________________________________________________________________________ Compare the physical and chemical properties of Salt with the properties of the elements that bond when it forms. d. Classify the following as a physical or chemical change: b. Example Using electricity to break H2O into H and O Dissolving salt in water Rust forming on a fence Water boiling Burning paper Baking cookies Heating table sugar Physical Chemical e. Chemical Reactions The left side of a chemical reaction is made up of reactants / products, the right side is reactants / products. f. Energy Transfer- Forms of energy: ___________________ ____________________ A change that gives off energy is called ________________________________ Example _____________________ A change that absorbs energy is called _________________________________ Example _____________________ g. TRUE / FALSE. The appearance of the reactants predicts the appearance of the products. h. Identify which of the following equations are balanced; if it is not balanced, balance it: _1_ Na3PO4 + _3_ KOH _3_ NaOH + _1_ K3PO4 ___ P4 + ___ O2 _2_ P2O3 ___ MgF2 + ___ Li2CO3 ___ MgCO3 + ___ LiF i. Identify the reactants and products from the following equation: ____ N2 + ____ H2 ____ NH3 2 RbNO3 + __ BeF2 __ Be(NO3)2 + 2 RbF 12. DNA a. Name the five atoms found in the DNA molecule: i. ______ ii. _____ iii. _____ vi. _____ v. _____ True/False questions: If false, re-write the corrected statement. b. TRUE / FALSE. DNA is a micromolecule. ____________________________________________________________________ c. TRUE / FALSE. DNA’s shape is a single helix. _________________________________________________________________ d. TRUE / FALSE. A-T and G-C are base pairs in DNA. ____________________________________________________________ e. TRUE / FALSE. DNA has a sugar-phosphate backbone. _________________________________________________________ 4