Dimensional Analysis
The distance from Earth to the Moon is approximately 240,000 miles. If the Concorde SST with an airspeed of about 2400 km/hr could fly to the Moon, how many seconds would it take? HINT: 0.621 mile =1 km
5.8x105 seconds
Energy is never created or destroyed in a chemical or physical change is known as?
Law of Conservation of Energy
37Cl- has how many protons, neutrons, and electrons
17 protons
20 neutrons
18 electrons
Rank the following in order of increasing energy
1. Gamma Rays
2. Red light
3. Microwaves
4. Ultraviolet
5. Yellow Light
3 < 2 < 5 < 4 < 1
How many significant figures are in: 0.00283
3
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.
8.34 L
The capacity to do work is known as?
Energy
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
A laser pulse with a wavelength of 532 nm contains 3.85 mJ of energy. How many photons are in the laser pulse?
1.03 x 1016 photons
Answer with a correct amount of significant figures: 2.56 + 5.6729 =
8.23
A balloon is filled with 49.4 g of helium. How many atoms of helium are in the balloon?
7.43 x 1024 atoms
A system in which energy is released is known as?
Exothermic
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%
What is the wavelength of radiation absorbed when an electron moves from the n = 3 level to the next energy level in a hydrogen atom?
1.88 um
Answer with the correct amount of significant figures: 41000/2.35 =
1.7 x 10^4 or 17000
A solid copper cube contains 8.6x1024 atoms. What is the edge length of the cube in inches? HINTS: 2.54 cm = 1 inch and the density of Cu = 8.96 g/cm3
1.8 in
What is the English unit of energy?
Calorie
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 20.57 grams? What mass of Cl-37 will be in a sample of chlorine that is 20.57 grams?
15.61 g of Cl-35
4.96 g of Cl-37
What is the de Broglie wavelength of an electron moving at 70. meters per hour? HINTS: Mass of electron = 9.1094 × 10-28 g
3.7 x 10-2 m
Answer with the correct amount of significant figures: 2.45 x 10^9 * 2.6738 x 10^6
6.55 x 10^15
A copper ingot weighs 150. pounds and is drawn into wire with diameter of 8.25 mm. How many feet of this copper wire can be obtained from this ingot? HINTS: The density of copper is 8.94 g/cm3 and 453.6 g = 1 pound; 2.54 cm = 1 inch; 12 inches = 1 foot V = (length)(pi)(radius)2 for a cylinder where pi = 3.1416
467 ft
What are the units associated with the Joule
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
The binding energy of a metal is 3.25x103 kJ/mol. A photon of wavelength 12.4 nm strikes its surface. What is the kinetic energy of an emitted electron in eV? HINT: 1 eV = 1.602x10-19 J
66.4 eV
Answer with the correct amount of significant figures: 4.562 x 3.99870 x (452.6755 - 452.33)
6.3