1. Review
Big Idea 1

2. 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

3. 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

4. Mole relationships
Moles and Molecules – 1 mol = x 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 ( L*atm/ mol*K)
At STP 1 mole= 22.4L

5. Molarity
Molarity (M)– Moles/L

6. 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

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

8. 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

9. Orbital Notation Diagram

10. 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

11. 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

12. 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)

13. Electron Configuration

14. Predicting Charge
Cations= positive ions
Anions = negative ions

15. 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

16. Periodic Trends
Number of Protons increases
Shielding increases

17. 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

18. 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

19. 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