Chemistry CDA #1 Review
Math Review:
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Understand unit conversions.
Know how to convert between all SI units, including temperature (Celsius to Kelvin).
Know how to calculate density.
Understand the difference between accuracy and precision and why they are important in chemistry lab.
Be able to use significant figures and scientific notation appropriately when calculating answers. Review your rules!!!
Physical and Chemical Properties and Changes:
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Know how to tell if a property is physical or chemical (can you observe it without changing it?). Understand why we need to know these
properties.
Know how to determine if a change is chemical and physical and what indications to look for when determining this (Is it reversible? Did
the properties change?)
Atomic Structure
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For each subatomic particle we discussed, be able to describe its charge, relative size, importance and location in the atom. Be able to
explain how the nucleus was discovered and what it is.
Know what gives an atom its identity
Be able to calculate mass numbers. Be able to show an element in Physicist’s Notation and Hyphen Notation.
Understand what an isotope is and the influence it has on atomic mass
Distinguish between fission and fusion.
Explain how fission can be used to create all elements larger than hydrogen
Know the difference between mass numbers and atomic masses. Be able to calculate an atomic mass from the mass of the isotopes and
the percent abundance of each isotope.
Electrons in Atoms Review
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History of Atomic Model: Know the differences between Rutherford, Thomson and Bohr’s atomic models. Be able to explain what was
wrong with each of them and to draw a simple example for each. Be able to explain what ‘Quantized’ energy levels means.
Quantum Numbers: Know the proper names for each quantum number and what information they provide about the electron location.
Know what Heisenberg’s uncertainty principle means. Be able to recognize the basic orbital shapes and know the number of different
orientations of the various shaped orbitals. Understand what spin is and why it is necessary.
Aufbau Principle: Know what the Aufbau principle says and how we use it. Be able to apply it when writing electron configurations.
Practice drawing that diagram!
Pauli Exclusion Principle: Know what this principle says and how we use it. Be able to apply it when writing electron configurations
Hund’s Rule: Know what Hund’s rule says and how we use it. Be able to apply it when writing orbital configurations
Configurations: Be able to write proper electron, orbital and noble gas configurations for any element. Be able to draw Lewis Dot
structures for any element that is not a transition metal. Be able to predict trends regarding valence electrons by looking at the periodic
table.
Light & Atomic Spectra: Understand that different wavelengths of light have different energy. Be able to explain why atomic spectra
prove that the energy in electron levels is quantized. Explain how atomic spectra are useful in identifying unknown substances.
PRACTICE PROBLEMS
1)
2)
3)
4)
Convert the following:
a. 3.4 L to mL
b. 45 m to cm
c. 876 mm to m
d. 11.7 g to kg
e.
f.
g.
h.
0.0009 kL to L
0.9 hg to g
44 cm to hm
277 kg to cg
How many significant figures are in each of the following?
a. 19
b. 910
c. 5000.0
d.
e.
f.
0.000720
606060
68400.20
Convert from scientific notation to a “regular” number
a. 1.204 x 10-5
b. 5.200 x 106
c.
d.
6.20 x 104
3.17 x 10-2
Convert to scientific notation
a. 16,000
b. 0.003500
c.
d.
0.000008210
981,000,000
5)
Perform the following calculations and round your answer to the appropriate number of significant figures.
a. 93.22 +18
e. 6.92 x 7.9
b. 72.8 - 70.4
f. 8.245 x 9.00
c. 107000 +190.079
g. 4.46 / 6.52
d. 446608.005 – 112230
h. 9.825 / 8.20
6)
List as many Physical and Chemical properties for oil as you can think of. Which properties would you use to distinguish between oil and
water?
7)
List one physical and one chemical change you could perform on the following items: your chemistry textbook, a glass of milk, a cup of
salt. EXPLAIN how you would KNOW it was a chemical/physical change.
8)
9)
A hot dog is cooked
a.
Chemical or physical change?
b.
Your reason:
Salt (NaCl) is dissolved in water
a.
Chemical or physical change?
b.
Your reason:
10) Water is boiled in preparation for making pasta
a.
Chemical or physical change?
b.
Your reason:
11) An element has three isotopes. The first isotope has a mass of 23.985 amu and an abundance of 78.99%. The second isotope has a mass
of 24.986 amu and an abundance of 10.00%. The third has a mass of 25.983 amu and a mass of 11.01% What is the element’s average
atomic mass? What element is it?
12) Using the data on the table below, calculate the average atomic mass of Magnesium.
mass number
exact mass (amu)
relative abundance (%)
24
23.985042
78.99
25
24.985837
10.00
26
25.982593
11.01
13) Draw a simple sketch for Rutherford, Thomson, and Bohr’s atomic models. Explain why each model is no longer used.
14) If opposite charges attract each other, why aren’t electrons drawn into the positively charged nucleus of an atom?
15) Sketch an example of an s, p and d orbital.
16) What information is given by 3p3?
17) How many valence electrons does each of the following have?
a.
barium
b. sodium
c. aluminum
18) How does atomic spectra illustrate that energy levels in atoms are quantized?
19) How can atomic spectra be used to determine the identity of an unknown chemical?
20) Draw Lewis Dot Structures for the following:
a.
N
b. Xe
c. Al
d. Na
21) Give the symbol for the atom whose electron configuration is shown below:
a.
1s22s22p63s23p6
b. 1s22s22p63s23p64s23d104p65s24d6
22) List the 4 quantum numbers for each of the following:
a.
Nitrogen
b. Boron
c. Argon
d. Magnesium