Electron Impact
Electron Impact - Related Videos
06:58
Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization
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2016
A method for electrochemically etching field emission tips is presented. Etching parameters are characterized and the operation of the tips in field emission mode is investigated.
01:19
Impact of Groups on Groups
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2025
Social psychologists analyze how groups influence one another, shaping social structures and interactions through both cooperation and competition. These dynamics manifest in various ways, ranging from economic partnerships to intergroup conflicts that shape societal structures and perceptions.Cooperation and Competition in Intergroup RelationsIntergroup relationships vary across contexts, sometimes fostering cooperation and mutual benefit while at other times leading to conflict and...
05:48
Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry
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Cited by 1 •
2014
This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.
01:24
Electron Carriers
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2019
Electron carriers can be thought of as electron shuttles. These compounds can easily accept electrons (i.e., be reduced) or lose them (i.e., be oxidized). They play an essential role in energy production because cellular respiration is contingent on the flow of electrons. Over the many stages of cellular respiration, glucose breaks down into carbon dioxide and water. Electron carriers pick up electrons lost by glucose in these reactions, temporarily storing and releasing them into the electron...
03:07
Electron Affinity
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2020
The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion). This process can be either endothermic or exothermic, depending on the element. Many of these elements have negative values of EA, which means that energy is released when the gaseous atom accepts an electron. However, for some elements, energy is required for the atom to become negatively charged, and the value of their EA is positive. Just as with ionization energy,...
FAQs
During electron impact ionization, an energetic electron removes a valence electron from a gas-phase molecule, creating a positively charged radical ion. The ion retains excess energy from the collision, and that energy can weaken or break particular chemical bonds. The resulting molecular and fragment ions reflect both the original molecule and the pathways available for its decomposition.
Fragmentation matters because the observed ions arise from the molecule’s chemical connectivity. A mass spectrum therefore contains more structural information than a molecular-ion signal alone: the combination of ion masses and their relative pattern can help distinguish compounds and support assignments based on how their bonds break. Reproducible patterns also enable comparison among measurements.
The balance depends on how much excess energy the molecular ion retains after electron impact and how readily its chemical bonds undergo cleavage. If fragmentation occurs, the spectrum contains ions representing both the intact molecular ion and separated structural portions. Examining their combined pattern helps relate the measured spectrum to molecular connectivity rather than relying on one peak.
The sample is introduced as a gas-phase molecule into a mass spectrometer, where energetic electrons ionize it. The instrument then records the resulting molecular and fragment ions as a mass spectrum. Analysts interpret the pattern by considering the ion signals and comparing the spectrum with reference information, using agreement to support compound identification and structural analysis.
Identification relies on the reproducibility of the molecular and fragment-ion pattern. An unknown compound produces a spectrum that can be compared with reference library spectra, allowing analysts to assess whether the observed ion distribution is consistent with a known substance. Because fragmentation reflects molecular connectivity, the comparison can also contribute evidence about structure.
Electron impact is particularly useful for compounds that can be converted to the gas phase without decomposing, especially volatile and thermally stable substances. In this setting, the technique supplies both molecular-ion and fragmentation information, supporting compound characterization, structural analysis, and comparison with reference libraries in analytical chemistry.