Skip to main content
Ch.8 - The Quantum-Mechanical Model of the Atom
Chapter 8, Problem 73

Ultraviolet radiation and radiation of shorter wavelengths can damage biological molecules because these kinds of radiation carry enough energy to break bonds within the molecules. A typical carbon–carbon bond requires 348 kJ/mol to break. What is the longest wavelength of radiation with enough energy to break carbon–carbon bonds?

Verified Solution

Video duration:
0m:0s
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Energy and Wavelength Relationship

The energy of electromagnetic radiation is inversely related to its wavelength, described by the equation E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength. This means that shorter wavelengths correspond to higher energy, which is crucial for understanding how radiation can break chemical bonds.
Recommended video:
Guided course
00:31
Frequency-Wavelength Relationship

Bond Energy

Bond energy is the amount of energy required to break a bond between two atoms. For carbon–carbon bonds, this energy is approximately 348 kJ/mol. Understanding bond energy is essential for determining the minimum energy required for radiation to effectively break these bonds.
Recommended video:

Calculating Wavelength from Energy

To find the longest wavelength of radiation that can break a carbon–carbon bond, one can rearrange the energy-wavelength relationship equation to λ = hc/E. By substituting the bond energy into this equation, one can calculate the corresponding wavelength, which indicates the threshold for bond-breaking radiation.
Recommended video:
Guided course
00:31
Frequency-Wavelength Relationship
Related Practice
Textbook Question

Calculate the frequency of the light emitted when an electron in a hydrogen atom makes each transition: a. n = 4 → n = 3 b. n = 5 → n = 1 c. n = 5 → n = 4 d. n = 6 → n = 5

8404
views
1
rank
Textbook Question

An electron in the n = 7 level of the hydrogen atom relaxes to a lower-energy level, emitting light of 397 nm. What is the value of n for the level to which the electron relaxed?

8547
views
5
rank
2
comments
Textbook Question

An electron in a hydrogen atom relaxes to the n = 4 level, emitting light of 114 THz. What is the value of n for the level in which the electron originated?

4995
views
2
rank
2
comments
Textbook Question

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. The change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. The minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kJ/mol. Calculate the longest wavelength visible to the human eye.

5685
views
2
comments
Textbook Question

An argon ion laser puts out 5.0 W of continuous power at a wavelength of 532 nm. The diameter of the laser beam is 5.5 mm. If the laser is pointed toward a pinhole with a diameter of 1.2 mm, how many photons travel through the pinhole per second? Assume that the light intensity is equally distributed throughout the entire cross-sectional area of the beam. (1 W = 1 J/s)

1008
views
Textbook Question

An X-ray photon of wavelength 0.989 nm strikes a surface. The emitted electron has a kinetic energy of 969 eV. What is the binding energy of the electron in kJ/mol? [KE = 1/2 mv2; 1 electron volt (eV) = 1.602×10–19 J]

3703
views
1
comments