Hydrocarbons vs functional groups 3 to recognize acids alcohol and amids Organic compounds Chapter 7 the quantum mechanical model of the atom Quantum mechanics Explains the manner in which electrons exist and behave in atoms Helps us understand and predict the properties of atoms that are directly related tot the behavior of the electrons Explains the behavior of the elements in chemical bonding Provides the basis for practical applications lasers computers etc Incredibly small Directly observing elections in the atom is impossible the electron is so small that observing it changes it s behavior Electrons have dual properties Behavior determines much of the behavior of atoms Particle Wave Electrons Electromagnetic radiation Light X ray Radio signals Microwaves Wave characteristics Wavelength the distance between successive crests or troughs m nm Frequency the number of cycles that pass through the stationary point in a given period of time 1 s hertz Hz Amplitude vertical height of the wave a measure of how intense the light is larger the amplitude the brighter the light Energy proportional to the amplitude of the waves and the frequency Larger amplitude more force wavelength has More frequently waves strike more energy they carry The electromagnetic spectrum Energy vs frequency vs wavelength The light energy is delivered to the atoms in packets called photons The energy of a photon of light is directly proportional to its frequency Inversely proportional to its wavelength Proportionality constant is called planck s constant 6 626 x 10 34 Color The color of light is determined by its wavelength or frequency White light is a mixture of all the colors of a visible light Red orange yellow green blue violet When an object absorbs some of the wavelengths of white light and re ects others it appears colored The observed color is predominantly the colors re ected Sunburns caused by high energy uv radiation Spectra High wavelength low frequency high energy The electromagnetic spectrum of an object is the characteristic distribution of electromagnetic radiation produced or consumed by that object A pattern of particular wavelengths of light that is observed is unique to that type of atom or molecule emission spectrum Can be used to identify the material ame test Examples reworks neon lights Rydberg s spectrum analysis and bohr s model The spectrum of hydrogen can be described with an equation that involves an inverse square of integers memorize The energy of an atom is quantized and that the amount of energy in the atom is related to the electron s position in the atom The electrons travel in orbits that are at a xed distance from the nucleus Stationary states The energy of the electron is proportional to the distance the orbit is from the nucleus the higher the orbit the higher the electron s energy An electron emits or consumes radiation when it jumps from one orbit to another The emitted or absorbed radiation is a photon of light The distance between the orbits determines the energy of the photon of light produced or consumed by the electron relocation Complementary properties of the electron When you try to observe the wave nature of the electron you cannot observe its particle nature and vice verse The wave and particle nature of the electron are complementary properties As you know more Determinacy vs indeterminacy According to classical physics particles move in a path determined by the particles velocity position and forces acting knit Determinacy Electron energy And position are complementary For an electron with a given energy the best we can do is describe a region in the atom of high probability of nding it The region distance from nucleus at which an electron with a particular amount of energy is likely to be found represents an orbital Quantum numbers Added to quantized the energy of the electron The size shape and orientation in space of an orbital are described by 3 integer numbers Quantum numbers Principle quantum number n Angular momentum l Magnetic ml Principle quantum number n Corresponds to Bohr s energy level characterizes the energy of the electron in a particular orbit N can be any integer greater than or equal to 1 The larger the value of n The more energy the orbital has The larger the orbital the further the electron is from the nucleus As n gets larger the amount of energy between orbitals gets s Allen Angular momentum quantum number l Determines the shape of the orbital L n 1 any value from 0 to n 1 Each value of l is called by a particular letter that determines shape of orbital S spherical P two balloons tied at knots D 4 balloons tied at knots F 8 balloons tied at knots Magnetic quantum number ml The direction in space the orbital is aligned relative to the other orbitals The magnetic quantum number is an integer that speci es the orientation of the orbital Values are integers from m l Including zero Gives the number of orbitals of a particular shape When l 2 the values of ml are 2 1 0 1 2 which means there are ve orbitals with l 2 Spin quantum number ms Describing an orbital Each set of n l ml and ms describes one orbital Orbitals with the same value of n are in the same principal energy level or principal shell Orbitals with the same values of n and l are said to be in the same sub level or sub shell Electron transitions predicting the spectrum of hydrogen To transition to a higher energy state you are consuming energy Light is emitted as electron falls back to lower energy level The wavelengths of lines in the emission spectrum of hydrogen can be predicted by calculating the difference in energy between any two states For an electron in energy state n there are n 1 energy states it can transition to Orbital shapes L 0 L 1 p orbitals Each principal energy leave has one s orbital Lowest energy orbital in a principal energy state Spherical Number of nodes n 1 Each principal energy state above n 1 has three p orbitals Ml 1 0 1 Two lobed Slightly higher energy than s orbitals L 2 d orbitals 5 d orbitals 4 lobed Oriented in space so electrons in the orbitals stay as far from each other as possible L 3 f orbitals 7 f orbitals Highest possible energy level within certain end Chapter 8 more on periodic table Periodic properties of elements Periodic law when elements are arranged in order of increasing atomic ass certain sets of properties recur periodically Mendeleevs periodic law allows us to predict the properties of am element based on the position on