Exam 1 Review and Core Concepts

Exam #1 Logistics & Core Topics

• Exam details:

  • Calculator and writing utensil are required.

  • No notes allowed during the exam.

  • Seating is assigned; seat numbers are located directly on the chairs.

  • No lab scheduled for the following week.

• Core topics for review:

  • Significant figures rules and calculations.

  • Metric conversions and English to Metric conversions.

  • Conversion factors for problem-solving.

  • Density calculations using $D = \frac{m}{V}$.

  • Wavelength and frequency relationships using $\lambda \times \nu = c$.

  • Energy relationships across colors and the electromagnetic spectrum.

  • Determining protons, neutrons, and electrons from the periodic table, and defining isotopes.

  • Chemistry history: Know one historical figure, their specific contribution, and the dates they lived.

Required Unit Conversions & Densities

• Conversions to memorize:

  • Mass: $1\,\text{lb} = 453.6\,\text{g}$

  • Distance: $1\,\text{in} = 2.54\,\text{cm}$ (exact)

  • Volume: $1\,\text{gal} = 3.785\,\text{L}$

  • Volume equivalence: $1\,\text{mL} = 1\,\text{cm}^3$ (exact definition)

• Key densities:

  • Osmium ($\text{Os}$): $22.59\,\text{g/mL}$ (element of greatest density)

  • Iridium ($\text{Ir}$): $22.56\,\text{g/mL}$

  • Mercury ($\text{Hg}$): $13.6\,\text{g/mL}$

  • Lead ($\text{Pb}$): $11.3\,\text{g/mL}$

  • Water ($\text{H}_2\text{O}$): Exhibits an unusual trend where solid ice is less dense than liquid water.

Metric Prefixes

• Positive powers of 10:

  • Deca ($\text{da}$): $10^1$

  • Hecto ($\text{h}$): $10^2$

  • Kilo ($\text{k}$): $10^3$

  • Mega ($\text{M}$): $10^6$

  • Giga ($\text{G}$): $10^9$

  • Tera ($\text{T}$): $10^{12}$

  • Peta ($\text{P}$): $10^{15}$

  • Exa ($\text{E}$): $10^{18}$

  • Zetta ($\text{Z}$): $10^{21}$

  • Yotta ($\text{Y}$): $10^{24}$

• Negative powers of 10:

  • Deci ($\text{d}$): $10^{-1}$

  • Centi ($\text{c}$): $10^{-2}$

  • Milli ($\text{m}$): $10^{-3}$

  • Micro ($\mu$): $10^{-6}$

  • Nano ($\text{n}$): $10^{-9}$

  • Pico ($\text{p}$): $10^{-12}$

  • Femto ($\text{f}$): $10^{-15}$

  • Atto ($\text{a}$): $10^{-18}$

  • Zepto ($\text{z}$): $10^{-21}$

  • Yocto ($\text{y}$): $10^{-24}$

Elements & Periodic Table Classification

• 56 elements to memorize (exact chemical symbols, approximate spelling of names, and classification):

  • Metals: Located on the left side of the periodic table.

  • Metalloids: Located along the staircase boundary.

  • Nonmetals: Located on the right side of the periodic table (along with Hydrogen, $\text{H}$).

• List of 56 required elements:

  • Hydrogen ($\text{H}$, atomic number 1)

  • Helium ($\text{He}$, 2)

  • Lithium ($\text{Li}$, 3)

  • Beryllium ($\text{Be}$, 4)

  • Boron ($\text{B}$, 5)

  • Carbon ($\text{C}$, 6)

  • Nitrogen ($\text{N}$, 7)

  • Oxygen ($\text{O}$, 8)

  • Fluorine ($\text{F}$, 9)

  • Neon ($\text{Ne}$, 10)

  • Sodium ($\text{Na}$, 11)

  • Magnesium ($\text{Mg}$, 12)

  • Aluminum ($\text{Al}$, 13)

  • Silicon ($\text{Si}$, 14)

  • Phosphorus ($\text{P}$, 15)

  • Sulfur ($\text{S}$, 16)

  • Chlorine ($\text{Cl}$, 17)

  • Argon ($\text{Ar}$, 18)

  • Potassium ($\text{K}$, 19)

  • Calcium ($\text{Ca}$, 20)

  • Scandium ($\text{Sc}$, 21)

  • Titanium ($\text{Ti}$, 22)

  • Vanadium ($\text{V}$, 23)

  • Chromium ($\text{Cr}$, 24)

  • Manganese ($\text{Mn}$, 25)

  • Iron ($\text{Fe}$, 26)

  • Cobalt ($\text{Co}$, 27)

  • Nickel ($\text{Ni}$, 28)

  • Copper ($\text{Cu}$, 29)

  • Zinc ($\text{Zn}$, 30)

  • Gallium ($\text{Ga}$, 31)

  • Germanium ($\text{Ge}$, 32)

  • Arsenic ($\text{As}$, 33)

  • Selenium ($\text{Se}$, 34)

  • Bromine ($\text{Br}$, 35)

  • Krypton ($\text{Kr}$, 36)

  • Rubidium ($\text{Rb}$, 37)

  • Strontium ($\text{Sr}$, 38)

  • Palladium ($\text{Pd}$, 46)

  • Silver ($\text{Ag}$, 47)

  • Cadmium ($\text{Cd}$, 48)

  • Indium ($\text{In}$, 49)

  • Tin ($\text{Sn}$, 50)

  • Antimony ($\text{Sb}$, 51)

  • Tellurium ($\text{Te}$, 52)

  • Iodine ($\text{I}$, 53)

  • Xenon ($\text{Xe}$, 54)

  • Cesium ($\text{Cs}$, 55)

  • Barium ($\text{Ba}$, 56)

  • Osmium ($\text{Os}$, 76)

  • Iridium ($\text{Ir}$, 77)

  • Platinum ($\text{Pt}$, 78)

  • Gold ($\text{Au}$, 79)

  • Mercury ($\text{Hg}$, 80)

  • Thallium ($\text{Tl}$, 81)

  • Lead ($\text{Pb}$, 82)

  • Bismuth ($\text{Bi}$, 83)

  • Polonium ($\text{Po}$, 84)

  • Astatine ($\text{At}$, 85)

  • Radon ($\text{Rn}$, 86)

Electromagnetic Spectrum & Light

• Seven main regions of the EM spectrum (ordered by decreasing wavelength / increasing frequency & energy):

  • Radio waves

  • Microwaves

  • Infrared

  • Visible light

  • Ultraviolet

  • X-rays

  • Gamma rays

• Visible light wavelength range:

  • Runs from $400\,\text{nm}$ (violet/blue end) to $700\,\text{nm}$ (red end).

• Fundamental equation:

  • $\lambda \times \nu = c$, where $c \approx 3.00 \times 10^8\,\text{m/s}$.

Questions & Discussion

• Attendance Question: How many neutrons does ${}_{19}^{39}\text{K}$ have?

  • A. 19

  • B. 20

  • C. 58

  • D. 39

  • Response: B. 20. ($\text{Neutrons} = \text{Mass number} - \text{Atomic number} = 39 - 19 = 20$).

• Practice Question 1: The number of __________ determines the identity of an element.

  • A. electrons

  • B. protons

  • C. neutrons

  • D. neutrons plus protons

  • E. protons plus electrons

  • Response: B. protons.

• Practice Question 2: A line in the spectrum of atomic mercury has a wavelength of $258\,\text{nm}$. When mercury emits a photon of light at this wavelength, the frequency of this light is:

  • A. $8.61 \times 10^{-16}\,\text{s}^{-1}$

  • B. $7.70 \times 10^{-19}\,\text{s}^{-1}$

  • C. $1.16 \times 10^{15}\,\text{s}^{-1}$

  • D. $77.3\,\text{s}^{-1}$

  • E. none of these are correct

  • Response: C. $1.16 \times 10^{15}\,\text{s}^{-1}$. Calculation: $\nu = \frac{c}{\lambda} = \frac{3.00 \times 10^8\,\text{m/s}}{258 \times 10^{-9}\,\text{m}} = 1.16 \times 10^{15}\,\text{s}^{-1}$.