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3 years ago

How many photons are produced in a laser pulse of 0.862 J at 691 nm?

1 answer:

4 0

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.

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Table salt contains 39.33 g of sodium per 100 g of salt. The U.S. Food and Drug Administration (FDA) recommends that adults cons

Naya [18.7K]

The individual can consume less than 184.6 g of the snack mix and still be within the FDA limit of salt consumption.

<h3>What is the mass of snack that can be consumed within the limit of sodium intake?</h3>

The mass of the snack mix that the individual can consume and still be within the FDA limit is calculated as follows:

U.S. Food and Drug Administration (FDA) recommends of sodium intake = less than 2.40 g of sodium per day.

Amount of salt in 100 g of snack mix = 1.30 g

Mass of snack that will contain 2.40 g of sodium = 2.40 * 100g/1.30 = 184.6 g of snack mix

Therefore, the individual can consume less than 184.6 of the snack mix and still be within the FDA limit of salt consumption.

In conclusion, the FDA recommends that an individual take in less than 2.40 g of sodium per day from their diet.

Learn more about salts at: brainly.com/question/23463868

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7 0

1 year ago

Elements placed in the same group have similar chemical properties. Which one of the following has different chemical property?

Westkost [7]

Answer:

Na has the different chemical property

3 0

2 years ago

Draw the curved arrow mechanism for the formation of an acetal from acidic methanol and 4-methylpentan-2-one in the fewest steps

morpeh [17]

Answer:

See explanation below

Explanation:

This reaction is known as Ketone hydrolisis in acid medium. This involves the formation of an hemi cetal, and then, the acetal. This is often used to convert ketones or aldehydes in ethers.

The first step involves the reaction with the acid. The carbonile reacts with the acid and forms an alcohol there. The next step is the reaction of the alcohol, in this case, the methanol to form the hemi cetal. Then in the third step, we repeat the first step, using acid to turn the OH group into a great leaving group such water. Then the water leaves the molecule, leaving the space wide open in the next step for methanol, and the acetal is formed.

See picture for the curved arrow mechanism

7 0

3 years ago

Cis-4-tertButylcyclohexyl bromide (compound 1) and Trans-4 tert Butylcyclohexylbromide (compound 2) are reacted with Potassium T

Mkey [24]

Answer:

In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the axial position and in compound 2 the Tert butyl occupies the axial and the bromine occupies equatorial positions. Compound 1 reacts faster than compound 2.

Explanation:

In cyclic organic compounds, substituents may occupy the axial or equatorial positions. The axial positions are aligned parallel to the symmetry axis of the ring while the equatorial positions are around the plane of the ring.

Bulky substituents have more room in the equatorial than in the axial position. This means that compound 1 is more stable than compound 2.

This is clear on the basis of stability of the molecules because compound 1 will react faster than compound 2 since the bulky tertiary butyl group in compound 1 occupy equatorial and not axial positions.

4 0

3 years ago

The gas law for an ideal gas at absolute temperature T (in kelvins), pressure P (in atmospheres), and volume V (in liters) is PV

allsm [11]

Answer:

The rate of change of the temperature is 0.0365 Kelvin per minute.

Explanation:

<u>Step 1</u>: Given data

ideal gas law: P*V = n*R*T

with P= pressure of the gas ( in atm) = 9.0 atm

with V= volume of the gass (in L) =12L

with n = number of moles = 10 moles

R = gas constant = 0.0821 L*atm* K^−1*mo^−1

T = temperature = TO BE DETERMINED

The volume decreases with a rate of 0.17L/min = dV/dT = -0.17

The pressure increases at a rate of 0.13atm/min = dP/dT

<u>Step 2:</u> The ideal gas law

P * [dV/dT] + V * [dP/dT] = nR * dT/dt

9 atm * (-0.17L/min) + 12L * 0.13atm/min = 10 moles * 0.0821 L*atm* K^−1*mo^−1 *dT/dt

0.03 = 0.821 * dT/dt

dT/dt = 0.03/0.821

dT/dt = 0.0365

Since the gas constant is expressed in Kelvin and not in °C, this means that <u>the rate of chagnge of the temperature is 0.0365 Kelvin per 1 minute.</u>

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3 years ago