Structure of the Atom
Structure of the Atom
The arrangement of electrons around the nucleus of an atom is known as its electronic structure. Since electrons determine all the chemical and most physical properties of an atomic system, it is important to understand the electronic structure. Much of our understanding has come from spectroscopy, the analysis of the light absorbed or emitted by a substance. Electromagnetic radiation is a form of energy; light is the most familiar type of electromagnetic radiation. But radio waves, microwaves, X-rays, and many other similar phenomena are also types of electromagnetic radiation. All these exhibit wavelike properties, and all travel through a vacuum at the speed of light. The wavelike propagation of electromagnetic radiation can be described by its frequency (ν), wavelength (λ), and speed (c). Wavelength (lambda, λ): The wavelength of a wave is the distance between two successive peaks or troughs. Frequency (nu, ν): The frequency of a wave is the number of waves (or cycles) that pass a given point in space in one second. The unit is expressed as the reciprocal of seconds (s−1) or as hertz (Hz). A hertz is one cycle per second (1 Hz = 1 s−1). Speed of light (c): The speed of light in a vacuum is one of the fundamental constants of nature, and does not vary with the wavelength. It has a numerical value of 2.9979 × 108 m/s, but for convenience we use 3.0 × 108 m/s. These measurements are related by the equation: Speed of light =Wavelength×Frequency c = λν This expression can be rearranged to give: λ = c/v, or ν = c/λ Wave number (⊽): The wave number is a characteristic of a wave that is proportional to energy. It is defined as the number of wavelengths per unit of length (usually in centimeter, cm).Wave number may be expressed as ⊽ =1/λ While electromagnetic radiation behaves like a wave, with characteristic frequency and wavelength, experiment has shown that electromagnetic radiation also behaves as a continuous stream of particles or energy packets.
Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.
If you think you should have access to this title, please contact your librarian.