CHEM 111: Final Study Guide 1/24/14- Chemistry is the study of matter, its properties, the changes that matter undergoes, and the energy associated with these changes.o by observing physical (behavior, apperence), and chemical (behavior, components) properties - Matter: anything that has both mass and volume - the “stuff” of the universe- Composition: the types and amounts of simpler substances that make up a sample of matter- Properties: the characteristics that give each substance a unique identity- Physical and chemical changes are accompanied by an energy change to/from the ground state - Physical Properties: properties a substance shows by itself without interacting with another substance - color, melting point, boiling point, densityo Not changing composition; reversible sometimes - Chemical Properties: properties a substance shows as it interacts with, or transforms into, other substances - flammability, corrosivenesso Changing composition, often irreversible - Total Energy = Potential Energy + Kinetic Energyo Potential Energy: is energy due to the position of an object.o Kinetic Energy: is energy due to the movement of an object. PE converted to KE via movement, velocity, heat o Lower energy states are more stable and are favored over higher energy states. o T(in K) = T (in C°) + 273.15o T(in °C) = T(in K) – 273.15o T(in °F) = 9/5 T (in °C) + 32o T(in °C) = [T (in °F) – 32] 5/9 - SI System: length (m), volume (L), mass (g)o 1mL = 1cm3 1/27/14- Significant Figures o Rule: figures are significant exceptplace holder zeroes o Ex: zeros that end a number aresignificant (before or after thedecimal point)o If no decimal is present, zeros are no significant  1.030 (4), 5300. (4) 5300 (2) 7.2000 (5) 720. (3) o Adding and subtracting: the answer has the same number of decimal places as .o there are in the original number; only digits after decimal (ex: 83.5 + 23.28 = 106.78, 106.8) o Multiplication and Division: the # of sig. figs. in the answer must equal the least # of sig figs from the measurement (ex. 10.7218/1.2=2 sig figs) all full digits  (2.5 m) x (2.01 m) x (2.755 m) = 13.843875 m → 14, 2 sig figs- Precision refers to how close the measurements in a series are to each other.o Low random error: no control of error - Accuracy refers to how close each measurement is to the actual value.- Systematic error produces values that are either all higher or all lower than the actual value. This error is part of the experimental system.o Calibration can help to decrease this - Random error produces values that are both higher and lower than the actual value.1/29.14 2.5 Atomic Theory - Daltons Atomic Theory:o 1. All matter consists of atoms; tiny indivisible particles of an element that cannotbe created or destroyed.o 2. Atoms of one element cannot be converted intoatoms of another element.o 3. Atoms of an element are identical in mass and otherproperties and are different from the atoms of any otherelement.o 4. Compounds result from the chemical combination ofa specific ratio of atoms of different elements.- Net charge = # of electrons, Element identity = # of protons- The Law of Conservation of Mass states that matter is neithercreated nor destroyed in a chemical reaction.- Proton; (p+) 1+ located in the nucleus; neutron (n0) 0 located in nucleus; electron (e-) 1- located outside the nucleus - X = atomic symbol of the element - A = mass number; # or protons + neutrons; A = Z + N- Z = atomic number (number of protons in the nucleus)- N = number of neurons in the nucleus - Isotopes are atoms of an element with the same number of protons but with a different number of neutrons (sameatomic number but different mass number)o A stable element is about balance between protons and neutrons  28Si has 14p+, 14e- and 14n0 (28-14) 29Si has 14p+, 14e- and 15n0 (29-14) = neutrons + protons  30Si has 14p+, 14e- and 16n0 (30-14)- Atomic Mass: is a weighted average of the naturally occurring isotopes of an atom o EX PROBLEM: Calculate Atomic mass from isotope mass and abundance:  Isotope Mass (amu) Abundance (%) 107Ag 106.90509 51.84 109Ag 108.90476 48.16 mass portion from 107Ag = 106.90509 amu x 0.5184 = 55.42 amu mass portion from 109Ag = 108.90476amu x 0.4816 = 52.45amu atomic mass of Ag = 55.42amu + 52.45amu = 107.87amu- 1 atomic mass unit = 1/12 of the mass of a carbon atom 12Co 1amu = 1 dalton (Da) = 1.66054X10^-242/3/14 2.6 The Periodic Table - Based on trends- Groups ↓↓↓, Periods →- Groups have similar chemical properties - Arranged by increasing atomic # (Z)-2/3/14, 2/5/14 7.1 The Wave Nature of light - Electromagnetic radiation: energygenerated by electric and magnetic fieldsthat increase and decrease in intensity asthey move through space - visible light is a type of electromagneticradiation - frequency (ν or nu), cycles per secondor (Hz)- wavelength (λ), the distance a wavetravels in one cycle (meters)- amplitude, the height of a wave crest or depth of a trough. o The higher the amplitude the brighter - λ = C/V or λV = C or V= C/ λ- Inversely proportional - Electromagnetic spectrum : (in meters), frequencyo A continuum of energy – radiant o In a vacuum all waves move travel at the same speed, but different frequency o Color – violet has the greatest energy – shortest wavelengtho Radio → lowest energy (longest wavelength); gamma ray → highest energy o Radio → microwave → infrared → visible → ultraviolet → X ray → gamma ray o (10^3) (10^-2) (10^-5) (.5x 10^-6) (10^-8) (10^-10) (10^-12) o (10^4) (10^8) (10^12) (10^15) (10^16) (10^18) (10^20)The speed of light is constant: c = ν x λ = 3.00 x 108 m/s in a vacuum- Distinction between energy and mattero 1. Refraction and dispersiono 2. Diffraction and interference o Bend and amount of refraction isdependent upon the wavelength(color), refraction index isdifferent  Shorter wavelength ↑energy ↑ frequency - EX PROBLEM: What is the wavelengthof a photon with a frequency of 2.45X 10^15 Hz?o 3.00 X 10^8 m/s / 2.46X10^15 Hz = 122 X 10^-9 m 2/3/14: 7.1 The Particle Nature of Light - 4 Types:o Refraction: the change in speed causes a change in directiono Dispersion: different waves travel at different speeds through the same thing “white light” made up, splitting into component colors – prism o Diffraction: waves bend around objects  Bending light also occurs when waves