1. Semester One Final Exam Review
Chemistry

2. Models of the Atom Dalton Thomson Rutherford Bohr Quantum
None – a solid sphere
Electrons – negative
Protons - positive
Thomson
Electrons – negative
Protons – positive
Nucleus of protons in center
Rutherford
Electrons – negative
Protons – positive
Neutrons - neutral
Nucleus of protons
Electrons orbit at different levels
Bohr
Electrons – negative
Protons – positive
Neutrons – neutral
Nucleus of protons and neutrons
Electrons in clouds
Quantum

3. Information from the Periodic Table3
atomic number
= number of protons (unique to element)
= number of electrons Li
lithium
atomic weight
= average mass of all isotopes
6.94
mass number (whole number)
= protons + neutrons

4. Isotopes
Isotopes: atoms of the same element with different numbers of neutrons
To find possible isotopes:
round the atomic weight down to the nearest whole number and up to the nearest whole number
neutron

5. Nuclear Reactions – Alpha and Beta Decay
Alpha Decay:
Beta Decay:
Key to remember:
the numbers on both sides of the arrow MUST balance (just like in chemical equations)

6. Valence Electrons
Valence electrons: electrons in the outermost (highest) energy level
For all elements EXCEPT THE TRANSITION METALS, use the column/group to determine the number of valence electrons.

7. Electron Configurations

8. Shorthand Electron Configurations
Instead of writing out all the filled subshells, you can use a shorthand (or noble gas) configuration.
Use the last noble gas as your starting point.
EXAMPLE:
Bromine’s full electron configuration: 1s22s22p63s23p64s23d104p5
Bromine’s shorthand configuration: [Ar]4s23d104p5
Bromine’s shorthand configuration: [Ar]4s23d104p5

9. Chemical Formula to Name
Steps to follow:
1. Ionic or covalent?
2. Covalent: use prefixes
3. Ionic: look for polyatomic ions and transition metals
MnO
manganese (II) oxide
P4O8
tetraphosphorous octaoxide
K2CO3
potassium carbonate

10. Chemical Name to Formula
Steps to follow:
1. Ionic or covalent?
2. Covalent: use prefixes
3. Ionic: write ion list and get charges to cancel out
Lead (IV) sulfide
PbS2
Calcium hydroxide
Ca(OH)2
Nitrogen dioxide
NO2

11. element + element → compound Synthesis A + B → AB + →
Type of Reaction
To identify…
element + element → compound
Synthesis
A + B → AB →
compound → element + element
Decomposition
AB → A + B →
element + compound → element + compound
Single Replacement
A + BX → AX + B →
compound + compound → compound + compound
Double Replacement
AB + CD → AD + BC →
Carbon compound + O2 → CO2 + H2O
Combustion
ALWAYS THE PRODUCTS!

12. Predicting Products Hints:
1. Identify the type of reaction so you know how many products to find
2. Circle polyatomic ions
3. Ionic compound charges must cancel out!
1. Mg + O2  MgO (synthesis)
2. NaCl + Al(NO3)3  NaNO3 + AlCl3 (double replace.)
3. Sr + H2SO4  SrSO4 + H2 (single replace.)

13. __AgNO3 + __Cu  __ Cu(NO3)2 + __Ag
Balancing Equations
Hints:
1. Start by drawing one of each compound and put a box around it. Remember – a capital letter means you have a new element!
2. Leave oxygen for last.
__AgNO3 + __Cu  __ Cu(NO3)2 + __Ag

14. Molar Mass 1. MnBr2 2. Sr(NO3)2 To determine…
1. How many of each atom?
2. Molar mass of each element?
3. Total mass from each element?
Then add them all together!
1. MnBr2
2. Sr(NO3)2
Used as a quick review on Day 2

15. Mole Conversions – a new trick!
Use the box method!
How many moles does a 25.2 gram sample of CaCl2 contain?
grams
molar mass
moles
Used as a quick review on Day 2

16. Mole Conversions – a new trick!
Use the box method!
What is the mass of 9.45 mol of Al2O3?
grams
molar mass
moles
Used as a quick review on Day 2

17. Stoichiometry – The Box Method
Calculate the number of grams of NH3 produced by the reaction of 11.9 g of nitrogen with an excess of hydrogen.
__N2 + __H2 → __NH3
grams
molar mass
moles