Review Big Idea 1

Homework Quiz – 15 questions PS 4 (chapter 7 questions) 30 38c 46b (if no 21b) 80a 109a Chapter 4 set 2 21b 29c 37d 43b Chapter 4 set 1 17b 56a 59a 65 Chapter 4 set 3 69f 71a 73d

Periodic Table Group IA/1 Alkali Metals Group IIA/2 Alkaline Earth Metals Group B/3- 12 Transition metals Group VIIA/17 Halogens Group VIII/18 Nobel Gases Offset underneath are Lanthanides and actinides (rare earth metals or inner transition metals.) #of Protons = atomic number, the identity of the element Change in number of neutrons, changes mass = isotopes average atomic mass takes into account isotopes and abundance Can be determined with Mass spectroscopy Change in electrons, changes charge = ions

Mole relationships Moles and Molecules – 1 mol = 6.022 x 10 23 particles Moles and grams – 1 mol = molar mass (g/mol) from periodic table Moles and gases – Mol = PV/RT Pressure (atm) V= Volume (L) T = temperature (K) R = gas constant (0.0821 L*atm/ mol*K) At STP 1 mole= 22.4L

Molarity Molarity (M)– Moles/L

Percent composition EX: Ca ( 𝑁𝑂 3 ) 2 Step 1 break up Step 2 Multiple number of atoms by atomic (molar) mass Ca: N: O: Step 3 Add up mass of indv. Elements (molar mass) of Compound Step 4 Divide each indv. Mass by total molar mass and 100% for percent comp

Empirical and Molecular Formula Empirical formula – simplest whole number ratio of one element to another in a compound

Electron Orbital Diagram Aufbau Principle – electrons are place in order of low to high energy in shells and sub shells Pauli exclusion principle – 2 electrons sharing an orbit cannot have the same spin Hund’s Rule – orbitals are filled singally first and then double up Think about empty seats on a bus, no one shares a seat if they can help it

Orbital Notation Diagram

Coulomb’s Law r E= k(+q)(-q) The amount of nrg an electron has depends on its distance from nucleus E= k(+q)(-q) r E= energy K = Coulomb’s constant +q = magnitude of positive charge -q = magnitude of negative charge r= distance between charges

Quantum Theory C= λ v E= hv or hc/λ E= nrg Energy of electromagnetic radiation E= hv or hc/λ E= nrg h= Planck’s Constant 6.63 x10^-34 v= frequency c=speed of light 3.00x10^8 m/s Frequency and wavelength C= λ v

Photoelectron Spectroscopy If an atom is exposed to EMR at energy levels that exceed the binding energies electrons can be ejected. The amount of energy to do this is called ionization energy (binding energy) Generally measured in eV (for atoms) or kJ/mol (for moles) Incoming radiation energy= Binding Energy + Kinetic energy (of ejected electron)

Electron Configuration

Predicting Charge Cations= positive ions Anions = negative ions

Theories Dalton- early 1800s proposed the idea of elements which are different and combine to for compounds 1869 Mendeleev and Meyer – Developed the periodic table independently arranging it by properties of elements J. J. Thomson – deflected charges in a cathode ray tube meaning atoms have positive and negative charge, negative charges are electrons, Plum Pudding model Millikan – oil drop exp. Calculated the charge of an electron by looking at its behavior (whole number charge ratios on each oil drop) Rutherford – early 1900s gold foil experiment, positive charge concentrated at the center nucleus and atoms are mostly empty space (model like on Jimmy Neutron) Heisenberg Uncertainty – impossible to know both position and momentum of an electron at any particular instant Schrodinger – is the cat dead or alive Electrons are in cloud regions and not in nice circles like Bohr predicted

Periodic Trends Number of Protons increases Shielding increases

Atomic Radius Left to right : decreases, protons are being added so electrons are more strongly attracted to the nucleus, little shielding Moving down : increases, due to shielding (electrons don’t like each other) Cations : are smaller atoms, electron repulsion is reduced Anions: are larger atoms, electron-electron repulsion increases

Ionization Energy Left to right : increases, protons are being added so electrons are more strongly attracted to the nucleus, harder to take away Moving down : decreases, due to shielding (electrons don’t like each other so the inner electrons block the outer electrons being pulled toward nucleus) Second ionization energy is greater than the first because electron-electron repulsion decreases

Electronegativity Refers to how strongly the nucleus of an atom attracts electrons of other atoms to bond with Left to right- increases Moving down - decreases