CH 101 1st Edition Exam 1 Study Guide Lectures 1 7 Lecture 1 January 7 Review the difference between atoms elements molecules compounds and moles An atom is the smallest component of an element all elements on the periodic table are atoms However when an atom such as oxygen is naturally bonded with its self like N2 O2 F2 Cl2 Br2 and I2 it is considered an element ad a molecule but not an atom Elements are a group of one or more of the same type of atom when the diatomic elements such as oxygen are written as O instead of O2 they are only considered an atom and not an element Molecules are made up of two or more atoms they can be the same element or different elements This differs from a compound because compounds are made up of two or more different atoms A mole represents 6 022x1023 objects weather that be moles or molecules Understand the molar mass of a molecule and how to find it I need to use the molar mass when you are asked to convert between moles and grams using stoichiometry The molar mass of a molecule is found by adding the atomic mass of the atoms that make up the molecule Use the molar mass when you need to convert between moles and grams In simple terms this is stoichiometry X amount of substance 1 ratio of substance 2 ratio of substance 1 Y amount of substance 2 In stoichiometry you can help yourself build your equation by knowing the units have to cancel out Lecture 2 January 9 How do you find the limiting reagent Which method should I use and how does it connect to Dalton s Atomic Theory The limiting reagent is found by 1 Balancing the equation 2 Convert the grams of each reactant to moles 3 Choose to solve through the drawing method by representing the amount of moles of each reactant with circles and then encircling the atoms of the reactant that make up the molecule or through the math method that replaces the drawings by using stoichiometry to find the amount of moles produced for each amount of reactant and comparing them to see which solution is smaller the smaller number is the limiting reagent Dalton s Theory confirms that the ratio between reactant and product is always maintained because he stated that atoms don t change composition during a chemical reaction He also stated that atoms are the smallest component of an element and that atoms combine to form molecules Lecture 3 January 12 What equations are important for finding the energy and the force of an electron and what do they tell me about the atom Coulomb s law of energy is E q1q2 r Coulomb s law of force is F q1q2 r2 q equals the charge of the particles and r equals the distance between them If the charges of the atoms are both negative they will spontaneously want to repel resulting in a lower energy the opposite goes for opposing charges When the energy decreases due to a spontaneous reaction the electron emits energy by jumping from a higher energy level to a lower one When a reaction is not spontaneous the electron increases in energy and jumps up to a higher energy level absorbing energy There are a couple columns on the periodic table you should know These families have similar properties like charge and reactivity Elements are in the center of the periodic table d block group 3 to group 12 are under the general category of metals but because they have different qualities from the rest of the metals they are known as transition metals Alkaline Earth metals belong in group 2 on the periodic table and are very reactive Halogens are in group 17 on the periodic table and are also highly reactive Noble gasses are in group 18 on the periodic table and are very stable elements because they have eight electrons in their outer shell Lecture 4 January 16 What are anions and cations and where can they be found on the periodic table Anions and cations are types of ions formed when an atom gains or loses electrons An anion occurs when the amount of electrons is more than the amount of protons in an atom making the atom negatively charged and are attracted to cations which are positively charged because they have less electrons than protons Focusing on the main groups cations are on the left side of the periodic table columns 1 2 is where the anions are located and the right side columns 13 17 Column 18 noble gases are neutrally charged Lecture 5 January 21 Explain the Identify important equations dealing with frequency wavelength and energy and describe the Bohr model of an atom The main equations you will be using to determine wavelength frequency energy and transition electron energy are c Etransition hR n2 low hR n2 high E h Elevel Z2 hR n2 Constants Wavelength Frequency c speed of light 3 00x10 8 m s E Energy in Joules h Plank s constant 6 626x10 34 J seconds R Rydberg s constant 3 29x1015 s 1 n2 low The lowest energy level and n2 high The highest energy level The Bohr model shows electrons as particles and has the energy levels as rings going outward from the nucleus of the atom As the energy levels get further and further from the nucleus the energy level get higher because the electron has to resist going toward the positively charged nucleus Lecture 6 January 23 Describe the difference between the Schrodinger and Bohr model of an atom and how the Schrodinger model uses quantum numbers to describe electron configuration The Schrodinger model shows the electrons in an atom moving in wave patterns instead of as particles The wavelength of a wave can be determined if you know the energy level of the electron the equation is 2L n where L is the length in centimeters The important quantum numbers are The s p d f energy levels are used in electron configuration to determine the amount of electrons in each orbital of the atom The rules to electron configuration include 1 The amount of electrons in the electron configuration must add up to the atomic number of the element 2 Electrons must be placed into the lowest energy level possible before going to the next energy level except for special cases like Cu and Co 3 Only two electrons can occupy an orbital and they must face opposite directions An electron configuration that has an incomplete orbital or has not filled an energy level but has an electron on the next energy level is in an excited state When the orbitals are all complete or at least occupied the electron are in a grounded state making them unreactive Lecture 7 January 26 What is the difference between a complete electron configuration and a valence electron configuration Explain effective