Photons
Calculate the energy of a single photon in a radio wave with a frequency of:
1.243 x 10-4 Hz
*Round to 3 sig figs
8.24 x 10-38 J
An element consists of 69.17% of an isotope with a mass of 62.930 amu and a second isotope with a mass of 64.928 amu. Identify the element
Copper or Cu
T/F An element with the electron configuration of [Ar]4s23d6 is a main group element
False; transition element
The density of iron is 7.87 g/mL. What is the mass 4.00 cm x 3.00 cm × 2.00 cm block
of iron? 1 mL = 1 cm3
188.88 g
What subshells do the different values for l correspond to?
l=0 --> s
l=1 --> p
l=2 --> d
l=3 --> f
When we see light from a neon sign, we are observing radiation from excited neon atoms.
If this radiation has a wavelength of 610 nm, what is the energy of the photon being
emitted?
*Round to 3 sig figs
3.26 x 10-19 J
Uranium has three naturally occurring isotopes: Uranium-238 (mass 238.05 amu), Uranium-235 (mass 235.04 amu), and Uranium-234 (mass 234.04 amu). Their respective fractional abundances are 99.27%, .719%, and .011%. Find the atomic mass of Uranium.
238.03 amu
What periodic table group do we use for shorthand electron configuration, and why?
Noble gasses: they reflect that every orbital up until that point is full.
How many cubic centimeters are there in 5.78 yd3? 1 in = 2.54 cm, 1 yard = 3 feet, 1 foot = 12 in
4.42 x 106 cm3
Write the full electron configuration for Ti (atomic number 22)
1s22s22p63s23p64s23d2
Calculate the energy of a photon (in kJ/mol) that has a frequency of 9.87 × 108 MHz
394 kJ/mol
Boron (B) has an average atomic mass of 10.81 amu and has two naturally occurring isotopes. Isotope 1 has an atomic mass of 10.013 amu and Isotope 2 has an atomic mass of 11.009 amu. What are the relative abundances of the respective isotopes? Give the answer as a percent.
Isotope 1 = 19.98%
Isotope 2 = 80.02%
Which of the following is considered a halogen?
Na
I
Ca
Kr
I
In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is
40.0 mi/gal, how many liters of gasoline would you need to buy to complete a 142-
km trip in Europe? Use the following conversions: 1km=0.6214mi and 1gal=3.78L
8.35 L
How many electrons can have the quantum numbers: n = 3, ml = +1
4
Calculate the de Broglie wavelength in pm of a xenon gas atom (Chemical symbol: Xe)
moving 498 m/s. Give your answer to 3 significant figures
6.07 pm
On earth, chlorine has two naturally occurring isotopes. Cl-35 with a mass of 34.9689 amu and Cl-37 with a mass of 36.9659 amu. What mass of Cl-35 will be in a sample of chlorine that is 41.24 grams? What mass of Cl-37 will be in a sample of chlorine that is 41.24 grams?
Cl-35 = 31.31 g
Cl-37 = 9.93 g
How many significant figures are in 1.5633300 x 1011 m?
8
You own a mini-cupcake shop and must consider your inventory. You currently have 8
50.0-lb bags of flour. Your mini-cupcake recipe requires 5.00 cups of flour and makes
173 mini-cupcakes. 1 pound of flour is 4.00 cups of flour. On average, each customer
purchases 78 mini-cupcakes. How many customers can you serve with your current stock
of flour? Round to the nearest whole number of customers
710 people
What is the shorthanded electron configuration of Bi (atomic number 83)
[Xe]6s24f145d106p3
An electron in a hydrogen atom jumps from n = 6 to n = 2. Calculate the frequency of the
electron in Hz.
7.31 x 1014 Hz
Silver is composed of two naturally occurring isotopes: Ag-107 (51.839%) and Ag-109. The ratio of the masses of the two isotopes is 1.0187. What is the mass of Ag-107?
106.905 amu
Determine the number of protons and neutrons in 226Ra
88 protons, 138 neutrons
After seeing a physician, a patient decides to add regular exercise and adjust his daily
calorie intake to lose 24.3 lbs of body fat. If 1.00 lb of body fat is lost for every 1.46 x
104 kJ of energy burned beyond what is consumed, how many days will it take for the
patient to meet his goal if he burns an additional 412 Calories per day than he consumes?
Give your answer rounded to the nearest day.
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1 calorie (cal) = 4.184 J ; 1 Cal = 1000 cal
206 days
What is the angular momentum number for the last electron in Hf (atomic number 72)
2