User Rating: 0 / 5

Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive
 

A molecular orbital higher in energy than any of the atomic orbitals from which it is derived, lends instability to a molecule or ion when populated with electrons, denoted with a star (*) superscript or symbol.

Latest Articles

  • What's In Your Beverage? How to Ensure Quality Control with CO2 Analytical Support

    Calibration standards, performance audits, and the FDA's never-ending safety, labeling, and inspection requirements are just the tip of the iceberg when it comes to dealing with the increasingly stringent quality control standards of the beverage industry. As these quality standards become...

  • Features of the Scanning Tunneling Microscope

    The scanning tunneling microscope (STM) invented by Heinrich Rohrer and Gerd Binnig in the 1980s still manages to do a great job today and competes with more advanced microscope types. The scanning tunneling microscope is used for studying the surface atoms that are found on various materials. The...

  • Chemical Safety

    People use chemicals every day for a wide array of purposes, which can include work and house hold duties. Many of us fail to realize that we are actually handling potentially deadly chemicals when we simply clean the bathroom or wash the car. This brings to mind the reason why chemical safety is...

  • Protein Design: Automated protein discovery and synthesis

    In this paper I describe (theoretically) the method(s) of automated protein discovery and synthesis.

  • Diamonds Are Forever

    Diamonds are still a girl's best friend, right? We love the shiny gems. They are the most popular rocks sold today. But what exactly are they, anyway? Where do they come from? What else are they used for?

Most Popular

Radiation

High energy particles or rays emitted during the nuclear decay processes.

Liquid Aerosol

Colloidal suspension of liquid in gas.

Gamma Ray

High energy electromagnetic radiation. A highly penetrating type of nuclear radiation similar to x-ray radiation, except that it comes from within the nucleus of an atom and has a higher energy. Energywise, very similar to cosmic ray except that cosmic rays originate from outer space.

xenon

A heavy, colorless, chemically inactive, monatomic gaseous element used for filling radio, television, and luminescent tubes. Symbol: Xe, at. wt.: 131.30, at. no.: 54.

Voltage

Potential difference between two electrodes, a measure of the chemical potential for a redox reaction to occur.

Dipole

Refers to the separation of charge between two covalently bonded atoms.

Isomorphous

Refers to crystals having the same atomic arrangement.

Diamagnetism

Weak repulsion by a magnetic field.

Anion

A negative ion, an atom or goup of atoms that has gained one or more electrons.

 

Coordination Isomers

Isomers involving exchanges of ligands between complex cation and complex anion of the same compound.

Hund's Rule

All orbitals of a given sublevel must be occupied by single electrons before pairing begins.

Electronic Transition

The transfer of an electron from one energy level to another.

Coulometry

The quantitative application of Faraday's Law to the analysis of materials. The current and time are the usual variables measured.

Standard Entropy

The absolute entropy of a substance in its standard state at 298 K.

Avogadro's Number

The number (6.022x10^23) of atoms, molecules or particles found in exactly 1 mole of substance.

Alkynes

Unsaturated hydrocarbons that contain one or more carbon-carbon triple bonds.

Condensed Phases

The liquid and solid phases, phases in which particles interact strongly.

Nucleons

Particles comprising the nucleus, protons and neutrons.

Acid

A substance that produces H+(aq) ions in aqueous solution. Strong acids ionize completely or almost completely in dilute aqueous solution. Weak acids ionize only slightly. Chemicals or substances having the property of an acid are said to be acidic.

Cathode Ray Tube

Closed glass tube containing a gas under low pressure, with electrodes near the ends and a luminescent screen at the end near the positive electrode, produces cathode rays when high voltage is applied.