________ is expressed in cycles per second, a unit also called a hertz (Hz)
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Bohr
________ assumed that electrons in hydrogen atoms move in circular orbits around the nucleus, but this assumption posed a problem.
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∆E
When ________ is negative, a photon is emitted as the electron falls to a lower- energy level.
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classical physics
According to ________, a charged particle (such as an electron) moving in a circular path should continuously lose energy.
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photoelectric effect
(1) the emission of light from hot objects (referred to as blackbody radiation because the objects studied appear black before heating), (2) the emission of electrons from metal surfaces on which light shines (the ________), and (3) the emission of light from electronically excited gas atoms (emission spectra)
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polychromatic source
A spectrum is produced when radiation from a(n) ________ is separated into its component wavelengths.
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higher energy
An increase in n also means that the electron has a(n) ________ and is therefore less tightly bound to the nucleus.
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Electrons
________ are emitted when photon energy exceeds the metal's work function.
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Schrödinger
________ treated the electron in a hydrogen atom like the wave on a plucked guitar string.
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Planck
________ won the 1918 Nobel Prize in Physics for his groundbreaking quantum theory.
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Radiation
________ composed of a single wavelength is monochromatic.
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quantum
________ (meaning "fixed amount) "to the smallest quantity of energy that can be emitted or absorbed as electromagnetic radiation.
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spectrum
A continuous visible ________ is produced when a narrow beam of white light is passed through a prism.
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quantum numbers
Electrons exist only in certain discrete energy levels, which are described by ________.
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Einstein
________ won the Nobel Prize in Physics in 1921 primarily for his explanation of the photoelectric effect.
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De Broglie
________ used the term matter waves to describe the wave characteristics of material particles.
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constant h
The ________ is called the Planck constant and has a value of 6.626* 10^- 34 joule second (Js)
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quantity mv
The ________ for any object is called its momentum.
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Energy
________ is involved in the transition of an electron from one level to another.
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Albert Einstein
In 1905, ________ (1879- 1955) used Plancks theory to explain the photoelectric effect.
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principal quantum number
The integer n, which can have whole- number values of 1, 2, 3,, ∞, is called the ________.
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X ray diffraction
________ occurs when X- rays pass through a crystal, creating a wave- like interference pattern.
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quantum mechanical model
An orbital (________, which describes electrons in terms of probabilities, visualized as "electron clouds) "is not the same as an orbit (the Bohr model, which visualizes the electron moving in a physical orbit, like a planet around a star)
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white light
The ________ could be sunlight or light from an incandescent lamp.
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Electrons
________ behave like waves because they are waves.
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photoelectric effect
To explain the ________, Einstein assumed that the radiant energy striking the metal surface behaves like a stream of tiny energy packets.
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Flashcard (32)