Ozone absorbs ultraviolet radiation in a part of the electromagnetic spectrum energetic enough to disrupt DNA in biological organisms and that is absorbed by no other abundant atmospheric constituent. This spectral range, denoted UV-B, spans the wavelengths of about \(290 \mathrm{~nm}\) to \(320 \mathrm{~nm}\). The molar extinction coefficient of ozone over this range is given in the table below (W.B. DeMore, S.P. Sander, D.M. Golden, R.F. Hampson, M.J. Kurylo, C.J. Howard, A.R. Ravishankara, C.E. Kolb, and M.J. Molina, Chemical kinetics aud photochemical data for use in stratospheric modeling: Evaluation Number 11, JPL Publication 94-26 (1994).

UV-B radiation refers to a specific part of the ultraviolet spectrum characterized by wavelengths from about 290 nanometers (m) to 320 nm. This range of ultraviolet light holds significant importance to life on Earth due to its capability to penetrate biological tissues and cause DNA disruption, which can lead to skin cancers and other cellular damage in living organisms. The ozone layer, situated in the Earth’s stratosphere, plays a critical protective role by absorbing the majority of this harmful UV-B radiation. Without this protective layer, the increased exposure to UV-B would have severe implications for ecosystems and human health.

It's crucial to distinguish UV-B radiation from other types of ultraviolet light such as UV-A and UV-C, which have different effects and are absorbed differently by atmospheric constituents. Unlike UV-A, which has a longer wavelength and is less harmful, UV-B has enough energy to affect the DNA molecules within cells directly, making understanding and measuring its interaction with ozone imperative for assessing environmental safety and the health of various life forms.

The molar extinction coefficient is a measurement that quantitatively describes how strongly a chemical species absorbs light at a particular wavelength. It is an intrinsic property of the substance and is vital for calculating the absorbance of light due to the presence of the substance in a medium. In the case of ozone and its capacity to absorb UV-B radiation, the molar extinction coefficient provides key information about how effective ozone molecules are at absorbing specific wavelengths within the UV-B spectrum.

In more technical terms, the molar extinction coefficient, denoted by the symbol \( \epsilon \), is defined as the absorbance of a solution at a given wavelength per unit concentration of the solute and path length of the light through the solution. Its units are typically expressed as liters per mole-centimeter (L/mol·cm). To calculate the absorbance of light due to ozone over the UV-B range, the values of the molar extinction coefficient for each wavelength within that range are needed. These values help scientists and environmentalists to monitor and predict how changes in the ozone layer may impact the levels of UV-B radiation that reach the Earth's surface.

DNA disruption refers to the damage caused to the DNA molecule structure, which can be induced by exposure to certain environmental factors, with UV-B radiation being a particularly potent agent. The DNA molecule is the hereditary material in humans and almost all other organisms. When the DNA absorbs UV-B radiation, it can result in the formation of abnormal chemical bonds within the molecule, most commonly between adjacent thymine bases, leading to the creation of thymine dimers.

These dimers can disrupt the regular DNA structure and function, which in severe cases can lead to mutations, cell death, or cancer if not properly repaired by the cell’s natural mechanisms. Understanding the effects of UV-B on DNA is crucial for developing strategies to protect against skin cancers and genetic damage in both humans and wildlife. The ability of the ozone layer to absorb UV-B radiation thereby protects the DNA in biological organisms from the potential disruptions caused by this high-energy light.

The electromagnetic spectrum encompasses all types of electromagnetic radiation, which are categorized by their wavelength or frequency. Ranging from very long radio waves to very short gamma rays, the spectrum also includes, in increasing order of energy, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. Each type of radiation within the spectrum has its own unique properties and effects on matter.

Ultraviolet radiation falls between visible light and X-rays on the spectrum and is itself divided into several ranges, with UV-B sitting between UV-A and UV-C. Understanding the properties of different parts of the electromagnetic spectrum allows us to utilize them effectively for various applications and technologies. It also helps us protect against the harmful effects of certain high-energy radiations, such as the UV-B, by monitoring atmospheric conditions, like the ozone layer's health, that influence their impact on the Earth's surface.