light and energy
A laser emits red light with a wavelength of 650 nm. What is the frequency of this light?
4.6 x 1014 s-1
what is the molar mass of CO2?
44.01 g/mol
Fill in the blank
(check tablet)
11
Convert 4500 mg to g.
4.5 g
A radio wave has a frequency of 7.50 x 108 s-1. What is the wavelength of this wave?
0.400 m
How many moles of aluminum (Al) are in 27.0 g Al?
1.00 mol Al
An atom has 20 protons, 20 neutrons and 20 electrons.
Is it electrically neutral? Name the symbol of the atom.
Yes; Ca (calcium)
Convert 3.75 km to m.
3750 m
Calculate the energy, in joules, of a photon with a wavelength of 450.0 nm.
4.42 x 10-19 J
How many atoms of iron (Fe) are in 2.50 mol Fe?
1.51 x 1024 atoms Fe
U-235
How many protons, neutrons, and electrons? (assume electrically neutral)
protons: 92
neutrons: 143
electrons: 92
Convert 0.0250 m to mm.
25.0 mm
Calculate the energy, in joules, of a photon with a wavelength of 525.0 nm.
3.78 x 10-19 J
What is the mass, in grams, of 3.01 x 1023 atoms of calcium (Ca)?
Boron has two naturally occurring isotopes, 10B (isotopic mass = 10.0129 amu) and 11B (isotopic mass = 11.0093 amu). Boron has an average atomic mass of 10.811 amu.
What is the percent abundance of Boron-10?
19.9%
Convert 6.50 x 105 μg to g.
0.650 g
Calculate the energy, in joules, of a photon with a wavelength of 375.0 nm.
5.30 x 10-19 J
How many atoms of copper (Cu) are present in 12.7 g Cu?
1.20 x 1023 atoms Cu
Copper has two naturally occurring isotopes, 63Cu (isotopic mass = 62.9296 amu) and 65Cu (isotopic mass = 64.9278 amu). Copper has an average atomic mass of 63.546 amu.
What is the percent abundance of Copper-63?
69.2%
A sample has a mass of 2.75 x 10-3 kg. What is its mass in mg?
2.75 x 103 mg