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Ch.6 - Electronic Structure of Atoms
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232당신이 사용하는 게 아니라요?교과서 변경
6장, 문제 29c

One type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (c) How many photons are in a 1.00 mJ burst of this radiation?

검증된 단계별 안내
1
Convert the energy of the burst from millijoules to joules. Remember that 1 mJ = 0.001 J.
Calculate the energy of a single photon using the formula: \( E = \frac{hc}{\lambda} \), where \( h \) is Planck's constant (6.626 \(\times\) 10^{-34} \(\text{ J s}\)), \( c \) is the speed of light (3.00 \(\times\) 10^8 \(\text{ m/s}\)), and \( \lambda \) is the wavelength in meters (325 nm = 325 \(\times\) 10^{-9} \(\text{ m}\)).
Determine the number of photons by dividing the total energy of the burst by the energy of a single photon: \( \text{Number of photons} = \frac{\text{Total energy}}{\text{Energy per photon}} \).
Ensure all units are consistent, particularly energy in joules and wavelength in meters, to maintain dimensional accuracy.
Perform the division to find the number of photons, ensuring to keep track of significant figures based on the given data.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Photon Energy

The energy of a photon is determined by its wavelength and can be calculated using the equation E = hc/λ, where E is energy, h is Planck's constant (6.626 x 10^-34 J·s), c is the speed of light (3.00 x 10^8 m/s), and λ is the wavelength in meters. For UV light at 325 nm, this relationship allows us to find the energy of a single photon.
추천 영상:
가이드 코스
01:40
Photon Energy Formulas

Conversion of Units

In chemistry, it is essential to convert units appropriately to ensure consistency in calculations. In this case, the energy burst of 1.00 mJ must be converted to joules (1 mJ = 0.001 J) to match the units used in the photon energy equation. This step is crucial for accurately determining the number of photons in the given energy burst.
추천 영상:
가이드 코스
01:56
Conversion Factors

Calculating Number of Photons

To find the number of photons in a given energy burst, divide the total energy by the energy of a single photon. This is expressed mathematically as N = E_total / E_photon, where N is the number of photons, E_total is the total energy in joules, and E_photon is the energy of one photon calculated from its wavelength. This calculation provides insight into the quantized nature of light.
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가이드 코스
01:22
Calculate Oxidation Numbers Example
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교과서 질문

One type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (a) What is the energy of a photon of this wavelength?

교과서 질문

One type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (d) These UV photons can break chemical bonds in your skin to cause sunburn—a form of radiation damage. If the 325-nm radiation provides exactly the energy to break an average chemical bond in the skin, estimate the average energy of these bonds in kJ/mol.

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교과서 질문

One type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (b) What is the energy of a mole of these photons?

교과서 질문

An AM radio station broadcasts at 1000 kHz and its FM partner broadcasts at 100 MHz. Calculate and compare the energy of the photons emitted by these two radio stations.

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교과서 질문

A diode laser emits at a wavelength of 987 nm. (a) In what portion of the electromagnetic spectrum is this radiation found? (b) All of its output energy is absorbed in a detector that measures a total energy of 0.52 J over a period of 32 s. How many photons per second are being emitted by the laser?

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교과서 질문

The energy from radiation can be used to rupture chemical bonds. A minimum energy of 192 kJ/mol is required to break the bromine–bromine bond in Br2. What is the longest wavelength of radiation that possesses the necessary energy to break the bond? What type of electromagnetic radiation is this?

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