CHEM 1 PDF

Dear God, Thank you for this day and for the opportunity to learn. Please help us to be good listeners and to pay attention to our teacher. Help us to remember what we learn and to use it to make the world a better place. Amen.  (GROUP CLAP) ______ presents COMPLETE ATTENDAN...

Dear God, Thank you for this day and for the opportunity to learn. Please help us to be good listeners and to pay attention to our teacher. Help us to remember what we learn and to use it to make the world a better place. Amen.  (GROUP CLAP) ______ presents COMPLETE ATTENDANCE (GROUP CLAP) ______ presents INCOMPLETE ATTENDANCE  Buddy, study time! Be a wise man! Playing in the lab, gonna be a scientist someday! You got smile on your face, science is the grace! moving your pen all over the place, singin’ We are. We are READY! x2 Match the name of the scientist below to the corresponding atomic model they proposed. Name of Scientist Atomic Model Quantum Mechanical Model John Dalton Miniature Solar System J.J Thompson Plum Pudding Ernest Rutherford Raisin Bread Neils Bohr Billiard Ball Broglie and Planetary Model Schrodinger  For example, Rutherford’s model could not explain why an object such as the iron scroll shown here first glows dull red, then yellow, and then white when heated to higher and higher temperatures. Limitations of Rutherford’s Atomic Model It explained only a few simple properties of atoms. It could not explain the chemical properties of elements. Neils Bohr (1983) Studied the light produced when atoms were excited by heat or electricity. Neils Bohr (1983) Over the next two years, Bohr constructed a model of the hydrogen atom with quantized energy levels. Bohr pictured the electron moving in circular orbits corresponding to the various allowed energy levels. He suggested that the electron could jump to a different orbit by absorbing or emitting a photon of light with exactly the correct energy content. FLAME TEST https://javalab.org/en/flame_test_en/ https://javalab.org/en/fireworks_en/ Electrons orbit the nucleus like planets orbit the sun. As long as an electron remains in a shell, it never gains or losses energy. The gain or loss of energy occurs within orbits only due to jumping of electrons from one energy level to another energy level. Light consists of electromagnetic waves. Electromagnetic radiation includes the following spectrum. What spectral lines do you see? What do you notice about the energy levels of an atom? Within each energy level are sublevels. These are labeled as s, p, d, and f. Notice that the number of sublevels in an energy level is equal to the no. of energy level. Within sublevels, there are orbitals. This is the final location where electrons reside. Each sublevel has specific number of orbitals. Complete the data table below: Defects of Bohr’s Atomic Model According to Bohr, the radiation results when an electron jumps from one energy orbit to another energy orbit, but he did not explain how this radiation occurs. Bohr’s theory explained the existence of various lines in H- spectrum, but it predicted that only a series of lines exist. Later on it was realized that the spectral lines that had been thought to be a single line was actually a collection of several lines very close to each other. Defects of Bohr’s Atomic Model Bohr suggested circular orbits of electron around the nucleus of H- atom but later it was proved that the motion of electron is not in a single plane, but it takes three- dimensional space. Bohr’s assumes that an electron in an atom is located at a definite distance from the nucleus and is revolving round it with definite velocity ex. It has fixed momentum. This idea is not in agreement with HEISENBERG’s UNCERTAINTY PRINCIPLE which states that it is impossible to determine the exact position and momentum of a particle simultaneously with certainty. Louis Victor De Broglie from France and Erwin Schrödinger from Austria, suggested that because light seems to have both wave and particle characteristics (it behaves simultaneously as a wave and as a stream of particle The kinetic and potential energies of an electron in an atom are described by the Schrodinger equation:  Principal Quantum Number (n) describes the size and energy of the orbital and relative distance from the nucleus. The possible values of n are positive integers (1, 2, 3, 4 and so on). n=1 n=2 When n increases: energy increases and the distance of the electron from the nucleus increases Angular Momentum Quantum number (l) describes the shape of the orbitals. Its value is related to the principal quantum number and has allowed value of 0 to (n-1) Magnetic Quantum number (ml) describes the orientation of the orbital around the nucleus. The possible values of ml depend upon the value of the l quantum number. The allowed values for ml are -l though 0 to +l. Spin Quantum number (ms) indicates the direction the electron is spinning. There are only two possible values for ms: +1/2 and -1/2. When two electrons are to occupy the same orbital, then one must have an ms = +1/2 and the other electron must have an ms = -1/2. These are spin paired electrons.  Name Quantum Restriction Range number Principle n Positive 1,2,3…… Quantum integer number Azimuthal l Zero and positive 0,1,2……… Quantum integers less Number than n Magnetic Ml Integers between – -l,…-1,0,+1,…+l Quantum l and +l number Spin orientation Ms Up or down + ½ or – ½ quantum number 1: If n = 7, what are the possible values of l ? 2. If n = 4 and l = 3, then what are the possible values of ml?  ELECTRON CONFIGURATION Electron configuration is the distribution of electrons of an atom Electron configuration 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p 8s  E l e c t ro n c o n f i g u ra t i o n M n e m o n i c s Si Susan Pumasok sa Pinto, Si Daddy Pumasok Sa Dilim, Paano Si Franky Daddy? Paano Si Daddy Franky? Paano Frank, Daddy Frank? Electron configuration 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p 8s MNEMONIC DEVICE memory techniques that systematically change difficult to remember material into more easily remembered material Electron configuration Mnemonics 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p 8s  Electron configuration Mnemonics Si Susan Pumasok sa Pinto, Si Daddy Pumasok Sa Dilim, Paano Si Franky Daddy? Paano Si Daddy Franky? Paano Frank, Daddy Frank?  Apartment Rules Electron Configuration Rules From the Bottom Up: Rooms must be filled from the Aufbau Principle: the electrons fill the available ground floor up. Fill the one room on the first floor orbitals from lowest energy to highest energy. before starting to put new tenants on the second In the ground state all the electrons are in the floor. Then fill the s room before the p rooms. At lowest possible energy level. higher floors the order might change a bit. Singles First: the owner of the building wants to Hund’s Rule: The electrons must be placed into have the tenants spread out as much as possible. the orbitals in such a way that no pairs are put For that reason singles are placed in rooms before together unless absolutely necessary. That is, couples. If couples must be placed into a room single electrons must be placed into boxes first then all of the other rooms on that floor must and then paired up if necessary. already have a single in them. Opposite Gender Only: When two people are Pauli Exclusion Principle: Electrons come in two placed in a room they must be of opposite varieties based on the direction they are genders. No men may room together and no ‘spinning’. There is an Up spin and a Down women may room together. This is an arbitrary rule spin. Up and Down spins are always paired on the part of the owners: in a just world we together and Up-Up or Down-Down wouldn’t have to follow it. But quantum mechanics combinations are not allowed. No two has nothing to do with justice. electrons can ever be in the same place at the same time.  Apartment Rules Electron Rules From the Bottom Up: Rooms must be filled from the Aufbau Principle: the electrons fill the available ground floor up. Fill the one room on the first floor orbitals from lowest energy to highest energy. before starting to put new tenants on the second In the ground state all the electrons are in the floor. Then fill the s room before the p rooms. At lowest possible energy level. higher floors the order might change a bit. Singles First: the owner of the building wants to Hund’s Rule: The electrons must be placed into have the tenants spread out as much as possible. the orbitals in such a way that no pairs are put For that reason singles are placed in rooms before together unless absolutely necessary. That is, couples. If couples must be placed into a room single electrons must be placed into boxes first then all of the other rooms on that floor must and then paired up if necessary. already have a single in them. Opposite Gender Only: When two people are Pauli Exclusion Principle: Electrons come in two placed in a room they must be of opposite varieties based on the direction they are genders. No men may room together and no ‘spinning’. There is an Up spin and a Down women may room together. This is an arbitrary rule spin. Up and Down spins are always paired on the part of the owners: in a just world we together and Up-Up or Down-Down wouldn’t have to follow it. But quantum mechanics combinations are not allowed. No two has nothing to do with justice. electrons can ever be in the same place at the same time. ACTIVITY time ! Write the Electron Configuration of the following elements.