Quantum Physics

How is it a substance can emit photons of visible light after absorbing ultra violet photons but not with infrared
radiation

The re-emitted photons must be of lessor energy (longer wavelength) than the incident photons.

In a one-photon absorption process, the absorbed photon must have more energy that the re-emitted visible photon. Infrared phtns have less energy thn visible ones because of their lower frequency.

When you irradiate a material with high-intensity infrared laser light, it IS possible to obtain visible emission, with negligible heating, because of multiple-photon absorption and scattering processes that can occur. You do not see this occur in everyday processes, but I have observed it in the laboratry. So, the premise of your question is not quite correct. Tell your teacher and score some extra brownie points.

  1. 👍
  2. 👎
  3. 👁

Respond to this Question

First Name

Your Response

Similar Questions

  1. Nuclear Chemistry

    The half- life of a positron is very short. it reacts with an electron, and the masses of both are converted to two gamma-ray photons: (0e+1)+ (0e-1)---> 2γ (the 0 in front of e is the mass # and behind it is the atomic #) (γ

  2. Chemistry- Dr. Bob

    Question 1 Calculate the wavelength (in nm) of the red light emitted by a neon sign with a frequency of 4.74 x 1014 Hz. A) 704 nm B) 158 nm C) 466 nm D) 633 nm E) 142 nm My answer: D.633 nm Question 2 How many photons are

  3. chemistry

    A 100-watt light bulb radiates energy at a rate of 100 J/s. (The watt, a unit of power or energy over time, is defined as 1 J/s.) If all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

  4. biology

    Which of the following is true of the light-dependent reaction but not of the light-independent reactiopn? a. also known as the Calvin cycle b. requires photons to occur c. stores energy for long term use d. produces carbohydrate

  1. Solar Energy Please Help

    Figure 1 shows a simplication of the AM1.5 solar spectrum at 1000W/m2. The spectrum is divided in three spectral ranges: A for 0nm

  2. science help PLS

    Which of the following types of stars started out on the main sequence with the largest initial mass? In Graph A, the curve peaks at 800 nm, in the red section of the visible light spectrum. In Graph B, the curve peaks at 550 nm,

  3. science help pls pls

    Which of the following types of stars is cooler than an orange main sequence? In Graph A, the curve peaks at 800 nm, in the red section of the visible light spectrum. In Graph B, the curve peaks at 550 nm, in the green section of

  4. physics

    If a 80 lightbulb emits 4.0 of the input energy as visible light (average wavelength 550 ) uniformly in all directions, estimate how many photons per second of visible light will strike the pupil (4.0 diameter) of the eye of an

  1. chem

    At noon on a clear day, sunlight reaches the earth\'s surface at Madison, Wisconsin, with an average power of approximately 4.00 kJ·s–1·m–2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how

  2. physics

    A 75 W light source consumes 75 W of electric power. Typically only about 5% of this energy is emitted as visible light of wavelength 600 nm. (a) Calculate the frequency of the emitted visible light. (b) How many photons per

  3. physics

    Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 478 nm, determine the number of photons per second per

  4. Science

    White light moves through a prism and separates into colors in the following order: red, orange, yellow, green, blue, and violet. Which of the following choices correctly describes why the violet ray is at the bottom while the red

You can view more similar questions or ask a new question.