Waves and the Bohr model
... experiment you shine light on a piece of metal and sometime electrons come flying off. The idea is a simple one. The electric field of light causes the electrons to oscillate. If they are oscillating with enough energy the can escape the metal (if they have more energy than the potential energy hold ...
... experiment you shine light on a piece of metal and sometime electrons come flying off. The idea is a simple one. The electric field of light causes the electrons to oscillate. If they are oscillating with enough energy the can escape the metal (if they have more energy than the potential energy hold ...
CHAPTER 3: The Experimental Basis of Quantum Theory
... Field emission: A strong external electric field pulls the electron out of the material. Photoelectric effect: Incident light (electromagnetic radiation) shining on the material transfers energy to the electrons, allowing them to escape. Electromagnetic radiation interacts with electrons within ...
... Field emission: A strong external electric field pulls the electron out of the material. Photoelectric effect: Incident light (electromagnetic radiation) shining on the material transfers energy to the electrons, allowing them to escape. Electromagnetic radiation interacts with electrons within ...
Trends in the Periodic Table
... – A whole energy level may be lost, or – There is less electron-electron repulsion (pushing away) between the electrons in different energy levels • The radius of an atom always increases when it gains an electron (becomes an anion -) – Increased electron-electron repulsion pushes the valence shell ...
... – A whole energy level may be lost, or – There is less electron-electron repulsion (pushing away) between the electrons in different energy levels • The radius of an atom always increases when it gains an electron (becomes an anion -) – Increased electron-electron repulsion pushes the valence shell ...
Lab Science 9 Pacing Guide
... 8. Use historical examples to explain how new ideas are limited by the context in which they are conceived; are often initially rejected by the scientific establishment; sometimes spring from unexpected findings; and usually grow slowly through contributions from many different investigators (e.g., ...
... 8. Use historical examples to explain how new ideas are limited by the context in which they are conceived; are often initially rejected by the scientific establishment; sometimes spring from unexpected findings; and usually grow slowly through contributions from many different investigators (e.g., ...
Chapter 2 Part 1 ppt
... corresponding to an atomic orbital • The conditions for a physically realistic solution: -One value for electron density/point -Continuous (does not change abruptly) -Must approach zero as r approaches infinity ...
... corresponding to an atomic orbital • The conditions for a physically realistic solution: -One value for electron density/point -Continuous (does not change abruptly) -Must approach zero as r approaches infinity ...
648 CHAPTER 17. ELECTRIC POTENTIAL ENERGY AND THE
... The expression for the average kinetic energy per particle is independent of the mass of the particle and depends only on the temperature and Boltzmann’s constant. Hence, oxygen molecules at the same temperature have the same average kinetic energy per particle. Note that since ...
... The expression for the average kinetic energy per particle is independent of the mass of the particle and depends only on the temperature and Boltzmann’s constant. Hence, oxygen molecules at the same temperature have the same average kinetic energy per particle. Note that since ...
GROUP QUIZ UNIT 04 NAMES I. Fill in the charts (1 point per blank
... If three electrons are available to fill three empty 2p atomic orbitals, how will the electrons be distributed in the three orbitals? one electron in each orbital two electrons in one orbital, one in another, none in the third three in one orbital, one in the other two cannot be predicted, determine ...
... If three electrons are available to fill three empty 2p atomic orbitals, how will the electrons be distributed in the three orbitals? one electron in each orbital two electrons in one orbital, one in another, none in the third three in one orbital, one in the other two cannot be predicted, determine ...
X-ray photoelectron spectroscopy
X-ray photoelectron spectroscopy (XPS) is a surface-sensitive quantitative spectroscopic technique that measures the elemental composition at the parts per thousand range, empirical formula, chemical state and electronic state of the elements that exist within a material. XPS spectra are obtained by irradiating a material with a beam of X-rays while simultaneously measuring the kinetic energy and number of electrons that escape from the top 0 to 10 nm of the material being analyzed. XPS requires high vacuum (P ~ 10−8 millibar) or ultra-high vacuum (UHV; P < 10−9 millibar) conditions, although a current area of development is ambient-pressure XPS, in which samples are analyzed at pressures of a few tens of millibar.XPS is a surface chemical analysis technique that can be used to analyze the surface chemistry of a material in its as-received state, or after some treatment, for example: fracturing, cutting or scraping in air or UHV to expose the bulk chemistry, ion beam etching to clean off some or all of the surface contamination (with mild ion etching) or to intentionally expose deeper layers of the sample (with more extensive ion etching) in depth-profiling XPS, exposure to heat to study the changes due to heating, exposure to reactive gases or solutions, exposure to ion beam implant, exposure to ultraviolet light.XPS is also known as ESCA (Electron Spectroscopy for Chemical Analysis), an abbreviation introduced by Kai Siegbahn's research group to emphasize the chemical (rather than merely elemental) information that the technique provides.In principle XPS detects all elements. In practice, using typical laboratory-scale X-ray sources, XPS detects all elements with an atomic number (Z) of 3 (lithium) and above. It cannot easily detect hydrogen (Z = 1) or helium (Z = 2).Detection limits for most of the elements (on a modern instrument) are in the parts per thousand range. Detection limits of parts per million (ppm) are possible, but require special conditions: concentration at top surface or very long collection time (overnight).XPS is routinely used to analyze inorganic compounds, metal alloys, semiconductors, polymers, elements, catalysts, glasses, ceramics, paints, papers, inks, woods, plant parts, make-up, teeth, bones, medical implants, bio-materials, viscous oils, glues, ion-modified materials and many others.XPS is less routinely used to analyze the hydrated forms of some of the above materials by freezing the samples in their hydrated state in an ultra pure environment, and allowing or causing multilayers of ice to sublime away prior to analysis. Such hydrated XPS analysis allows hydrated sample structures, which may be different from vacuum-dehydrated sample structures, to be studied in their more relevant as-used hydrated structure. Many bio-materials such as hydrogels are examples of such samples.