C2 Revision Quick Questions FT
... Metallic bonding Shape memory Alloys can return to their original shape after being deformed, eg Nitinol used in dental braces. Different sized atoms do not form a regular pattern. Metals • Metals consist of giant structures of atoms arranged in a regular pattern. Alloys • Alloys are usually made f ...
... Metallic bonding Shape memory Alloys can return to their original shape after being deformed, eg Nitinol used in dental braces. Different sized atoms do not form a regular pattern. Metals • Metals consist of giant structures of atoms arranged in a regular pattern. Alloys • Alloys are usually made f ...
C2 Revision Quick Questions FT
... Metallic bonding Shape memory Alloys can return to their original shape after being deformed, eg Nitinol used in dental braces. Different sized atoms do not form a regular pattern. Metals • Metals consist of giant structures of atoms arranged in a regular pattern. Alloys • Alloys are usually made f ...
... Metallic bonding Shape memory Alloys can return to their original shape after being deformed, eg Nitinol used in dental braces. Different sized atoms do not form a regular pattern. Metals • Metals consist of giant structures of atoms arranged in a regular pattern. Alloys • Alloys are usually made f ...
Chapter 7 Covalent Bonding Outline Covalent Bonding Introduction
... 1. Count the number of valence electrons 2. Draw a skeleton structure for the species, joining the atoms by single bonds 3. Determine the number of valence electrons still available for distribution 4. Determine the number of valence electrons required to fill out an octet for each atom (except H) i ...
... 1. Count the number of valence electrons 2. Draw a skeleton structure for the species, joining the atoms by single bonds 3. Determine the number of valence electrons still available for distribution 4. Determine the number of valence electrons required to fill out an octet for each atom (except H) i ...
Coulomb blockade in the fractional quantum Hall effect regime *
... Despite enormous theoretical and experimental effort during the past decade, the nature of transport in the fractional quantum Hall effect 共FQHE兲 regime of the two-dimensional electron gas1 remains uncertain. Although chiral Luttinger liquid 共CLL兲 theory2,3 has successfully predicted transport and s ...
... Despite enormous theoretical and experimental effort during the past decade, the nature of transport in the fractional quantum Hall effect 共FQHE兲 regime of the two-dimensional electron gas1 remains uncertain. Although chiral Luttinger liquid 共CLL兲 theory2,3 has successfully predicted transport and s ...
full piece
... interviews we found that these students selected a wide range of answers. Some students who held both views decided that A, B, and C were all correct, while others picked only one or two of these options, either at random or because one sounded slightly more plausible. Several students changed their ...
... interviews we found that these students selected a wide range of answers. Some students who held both views decided that A, B, and C were all correct, while others picked only one or two of these options, either at random or because one sounded slightly more plausible. Several students changed their ...
Chemical Bond Activation Observed with an X
... and one 2−3 eV wide peak, which is at higher energy and completely unoccupied. Those two features can be directly related to the simple concept of bonding and antibonding molecular orbitals. In Figure 2a, we display in detail the electronic structure of atomic oxygen adsorbed on a ruthenium surface ...
... and one 2−3 eV wide peak, which is at higher energy and completely unoccupied. Those two features can be directly related to the simple concept of bonding and antibonding molecular orbitals. In Figure 2a, we display in detail the electronic structure of atomic oxygen adsorbed on a ruthenium surface ...
Weiguang Zhang 1,* Yun Zhong 1, Minyu Tan 2,*, Ning Tang 2 and
... been assigned to the carbon in the alkyl and the latter to the CSS. Its N(1s) spectrum showed a single full-width peak, but the S(2p) spectrum showed a broad peak with a shoulder suggesting two types of sulfur atoms. The two peaks indicated by the broken lines, which were obtained by a graphical res ...
... been assigned to the carbon in the alkyl and the latter to the CSS. Its N(1s) spectrum showed a single full-width peak, but the S(2p) spectrum showed a broad peak with a shoulder suggesting two types of sulfur atoms. The two peaks indicated by the broken lines, which were obtained by a graphical res ...
(1/V m C) +
... The electrons interact with atoms in the sample, producing various signals that contain information about the sample's surface topography and composition. ...
... The electrons interact with atoms in the sample, producing various signals that contain information about the sample's surface topography and composition. ...
Chapter 15 PowerPoint
... Fraunhofer lines on solar spectrum later realized to be absorption spectra of all of the gases in the cooler outer atmosphere of the Sun Elements identified by comparing individual elements’ spectra with lines on the solar spectrum ...
... Fraunhofer lines on solar spectrum later realized to be absorption spectra of all of the gases in the cooler outer atmosphere of the Sun Elements identified by comparing individual elements’ spectra with lines on the solar spectrum ...
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.