Photons
Calculate the energy of a single photon in a radio wave with a frequency of:
1.243 x 10^-4 Hz
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
Which of the following is/are true?
A) Two isotopes of the same element have the same atomic number, but different mass numbers.
B) Two isotopes of the same element have the same number of neutrons, but a different number of protons.
C) An electrically neutral atom has the same number of neutrons and electrons.
D) An anion has more electrons than protons
A & D
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
How many protons are in 36Cl-?
17
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?
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
Which of the following is/are true?
A) Orange light has a longer wavelength than violet light.
B) One photon of ultraviolet radiation has more energy than one photon of gamma rays.
C) Radio waves have a higher frequency than xrays.
D) As the energy of light increases, the frequency, and wavelength decrease.
A
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
How many atoms of Ag are in 97.4 ng of Ag?
5.44 x 1014
Calculate the energy of a photon (in kJ) that has a frequency of 9.87 × 108 MHz
6.54 x 10-22 kJ
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/are true.
A) A law describes what happens in nature; a theory describes why/how something happens.
B) "Chlorine is a highly reactive gas" is an example of observation.
C) Law of conservation of matter does not apply to the combustion of a log in a campfire because the mass of the log is much greater than the mass of the ashes that remain.
D) Chlorine gas is an example of a pure substance; it is classified as an element and exists as a molecule.
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
Calculate the Broglie Wavelength of a krypton gas atom which is 392 m/s
1.216 x 10-11
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
6.10 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
Which is of the following is/are true
A) 40.3 g of MgO decomposes to produce 24.3g Mg + 16.0g O gas, law of proportion would allow you to predict the ratio by mass of magnesium to oxygen in a 156g sample of MgO.
B) The Law of multiple proportions applies when you compare CO2 and NO2
C) H2O with table salt dissolved in it is an example of a heterogeneous mixture.
D) Solids have an indefinite shape and volume; liquids have a definite volume, but an indefinite shape; gases have a definite shape and volume.
A
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
An engineering firm has a custom unit of mass for a client called "BOBS" calculate the mass in BOBS of 0.256 Gg.
Hint: 12.4 Bobs = 4.50 x 1012 μg
705
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
Which of the following is/are true.
A) According to Dalton's Atomic theory, an atom of a carbon cannot change into an atom of nitrogen.
B) Rutherford's gold foil experiment proved the plum pudding model of the atom; showing atoms contain electrons embedded in a sphere of positive charge.
C) J.J Thomson's cathode ray experiment showed the existence of electrons and calculated their charge to mass ratio.
D) Milkan's oil drop experiment determined the charge of an electron by suspending charged oil droplets using an electric field.
A, C, & D
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 orbitals do the different values for l correspond to?
l=0 --> s
l=1 --> p
l=2 --> d
l=3 --> f