To calculate how many photons are in a certain amount of energy (joules) we need to know how much energy is in one photon.
Start by using two equations:
Energy of a photon = Frequency * Planck's constant (6.626 * 10^(-34) J-s)
Speed of light (constant 3 * 10^8 m/s) = Frequency * Wavelength
Which means:
frequency = Speed of Light / Wavelength
So energy of a photon = (Speed of light * Planck's constant)/(Wavelength)
You may have seen this equation as E = hc/<span>λ</span>
We have a wavelength of 691 nm or 691 * 10^-9 meters
So we can plug in all of our knowns:
E = (6.626 * 10^(-34) J-s) * (3.00 * 10^8 m/s) / (691 * 10^-9 m) =
2.88 * 10^(-19) joules per photon
Now we have joules per photon, and the total number of joules (0.862 joules)
,so divide joules by joules per photon, and we have the number of photons:
0.862 J/ (2.88 * 10^(-19) J/photon) = 3.00 * 10^18 photons.
Answer:
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Answer:
A. SI units allow scientists to communicate around the world using the same
system of measurement.
Explanation:
Answer:
7.335 moles of Cl₂ are required to react with 4.89 miles of Al.
Explanation:
Given data:
Moles of Al = 4.89 mol
Number of moles of Cl₂ required = ?
Solution:
Chemical equation:
2Al + 3Cl₂ → 2AlCl₃
Now we will compare the moles of Al and chlorine from balance chemical equation.
Al : Cl₂
2 : 3
4.89 : 3/2×4.89 =7.335 mol
Thus, 7.335 moles of Cl₂ are required to react with 4.89 miles of Al.
Answer:
I'm sure it's option A. Cast Fossil
