CHM 103 1nd Edition Exam 1 Study Guide Lectures 1 5 Lecture 1 September 3 Introduction to Atoms and Molecules What is an atom What is a molecule How do these two things correlate with matter Atom An atom is the fundamental building blocks of ordinary matter They are minuscule particles that can also bind together An example of an atom would be an oxygen atom or a carbon atom Molecule A molecule is a combination of atoms held together in specific shapes The properties of substances depend on the atoms and molecules that compose the substance An example of a molecule would be a carbon monoxide molecule How they Correlate with Matter Matter is built up of molecules and atoms Matter is what occupies space and without molecules and atoms there would be no matter The science of chemistry studies the behavior of matter by studying the behavior of atoms and molecules Lecture 2 September 5 More on Matter What are the three different classifications of matter Describe the molecules state in each classification Describe what a chemical and physical property is Describe what a chemical and physical change is Classify matter according to its composition Three Classifications of Matter Solid Molecules are tightly packed together and vibrate but do not move The solid has a fixed volume and a rigid shape Liquid Molecules and atoms are still packed closely together but are free to move around each other Therefore liquids have a fixed volume but not a fixed shape They assume the shape of their container Gas Molecules and atoms have a lot of room to move around rapidly This cause a lot of collisions between the molecules and atoms Gasses are compressible and always assume the shape and volume of the container they are in Physical and Chemical Properties Physical Properties Property that a substance displays without changing its composition Examples would be color odor density hardness melting and boiling point conductivity or solubility Chemical Properties Property that a substance displays only by changing its composition via a chemical change Examples would be corrosiveness flammability acidity toxicity etc Physical and Chemical Changes Physical Changes Changes that alter only state or appearance but not composition Atoms or molecules making up a substance do not change their identity in a physical change An example would be when water boils it changes its state from a liquid to a gas but the gas remains composed of water molecules Chemical Changes Changes that alter the composition of matter Atoms rearrange transforming the original substances into different substances An example would be the burning of propane gas Propane changes to carbon dioxide and water when it is burned Matter according to its composition Pure substance Composed of only a single type of atom or molecule Pure substances can be categorized into two types elements and compounds Element Substance that cannot be chemically broken down into a simpler substance An example would be Helium Compound Substance composed of two or more elements in fixed definite proportions An example would be pure water Mixture Composed of two or more types of atoms or molecules that can be combined in variable proportions Mixtures can also be categorized into two types heterogeneous and homogeneous depending on how uniformly the substances within them mix Heterogeneous Composition varies from one region of the mixture to another An example would be wet sand Homogeneous Holds the same composition throughout the entire mixture An example would be tea with sugar Lecture 3 September 8 Units Significant Figures and Density Memorize specific units of measurements What is a prefix multiplier What are the formulas for converting different temperatures How does one measure density What are significant figures and how do they work How does one solve a chemical problem Units of Measurements to Remember Quantity Length Unit Meter Kilogra m Second Kelvin Symbol m Mole mol Prefix kilo centi milli micro Symbol k c m nano n Multiplier 1000 0 01 0 001 0 000001 0 00000000 1 Mass Time Temperature Amount of Substance kg s K 10x 10 10 10 10 10 Prefix Multiplier Prefix multipliers change the value of the unit by powers of 10 such as an exponent does in scientific notation For example 1 kilometer 1000 meters 10 meters Formulas for Converting Temperature Celsius Fahrenheit C 9 5 32 F Fahrenheit Celsius F 32 x 5 9 C Celsius Kelvin C 273 15 K Density Formula Density d of a substance is the ratio of its mass m to its volume V So by knowing the volume and mass of a substance one can divide the two to find the density It is an example of an intensive property or one that is independent of the amount of the substance Mass in measure in grams g and volume is measured in either centimeters cubed cm or milliliters mL Significant Figures and their Rules 1 2 3 4 5 6 Significant figures sig figs are the non holding place digits that are not marking the decimal place recorded in any measurement Certain rules to follow when using sig figs are as follows All nonzero digits are significant Interior zeroes are significant Leading zeroes or zeroes to the left of the first nonzero digit are not significant They only serve as place holders for the decimal point Trailing zeroes after a decimal point are always significant Trailing zeroes before a decimal point but also after a nonzero number are always significant Trailing zeroes before an implied decimal point are ambiguous and should be changed to scientific notation Examples for each rule are as follows 1 23 05 and 0 0230 2 503 and 4 0401 3 0 0032 and 0 000005 4 43 000 and 2 3400 5 120 00 and 3400 44 6 1200 ambiguous 1 2 X 10 2 sig figs 1 20 X 10 3 sig figs 1 200 X 10 4 sig figs Solving Chemical Problems Units behave just like numbers in math What data are we given What quantity do we need What conversion factors are available to take us from what we are given to what we need Formula Given Unit Desired Unit Desired Unit Given Unit Lecture 4 September 10 The Atomic Theory Elements and the Periodic Table What is the Atomic Theory What were the laws that led up to the Atomic Theory What is the structure of an atom What is an Isotope What is an Ion How is the Periodic Table arranged and how does one read it The Atomic Theory The Atomic Theory states that all atoms of an element have the same properties which are different from those of other elements Atoms combine in simple whole number ratios to form compounds In chemical reactions atoms are