A container with 0.2450.245 L of water is placed in a microwave and radiated with electromagnetic energy with a wavelength of 10.510.5 cm. The temperature of the water rose by 69.969.9 °C. Calculate the number of photons that were absorbed by the water. Assume water has a density of 1.00 g⋅mL−11.00 g·mL−1 and a specific heat of 4.184 J⋅g−1⋅°C−14.184 J·g−1·°C−1.   number of photons =__________________________________photons

Light in the infrared portion of the electromagnetic spectrum excites vibrations of certain molecules, causing them to move more rapidly. In this manner, infrared light can be used to heat a substance. If a 1000.-mW, 808-nm laser is used to heat a 50.0-mL sample of water from 22.0 o C to its boiling point, a) how many photons will the water absorb and b) what is the minimum amount of time this will take?

Electromagnetic radiation with a wavelength of 575 nm appears as yellow light to the human eye. If a laser emits 3.8 x 1016 photons of this energy in a pulse, what is the energy of the pulse in mJ?

Water is exposed to infrared radiation of wavelength 2.8×10−4 cm . Assume that all the radiation is absorbed and converted to heat. How many photons will be required to raise the temperature of 2.1 g of water by 2.3 K ? Express your answer using two significant figures.

An x-ray has a wavelength of 6.88 nm. Calculate the energy of one mole of photons of this radiation in MJ (megajoules).

Your calibrated soup container has served you pretty well over the last several weeks, so you have decided to use it to heat up your soup for lunch using the microwave oven located just outside your lab. The oven warms food by delivering electromagnetic radiation with a frequency of 2.45 GHz at a rate of 7.39 x 10^26 photons per second. Your soup has a mass of 524 grams and your calibrated container has a heat capacity of 69.9 J °C-1. If the initial temperature of your soup is 25 °C, what will be its temperature if you allow it to heat in the microwave for 1.5 minutes? [Assume that the specific heat capacity of your soup is 4.18 J g-1 °C-1.]

W 4. (a) A laser emits light that has a frequency of 4.69 X 10¹4 s¹. What is the energy of one photon of this radiation? V (b) If the laser emits a pulse containing 5.0 X 1017 photons of this radiation, what is the total energy of that pulse? (c) If the laser emits 1.3 X 10-2 J of energy during a pulse, how many photons are emitted?

An electron in a hydrogen atom travels from energy level n = 2 to energy level n = 3.   Would the electron be absorbing or emitting this energy in this transition? What is the change in energy (ΔE) for this transition?   Show all work, including units and signs, and give your answer for ΔE to three significant figures.

the microwaves in an oven are of a specific frequency that will heat the water molecules contained in food.  (this is why most plastics and glass do not become hot in microwaves; they do not contain water molecules.)  This frequency is about 3 X 109 Hz.  What is the energy of one phonon in these microwaves?  Show calculations

A photon of light from a laser has an energy of 2.287 × 10−19 J. What is the total energy in two moles of these photos?