Discovered : by Sir William Ramsay in London, and independently by P.T. Cleve and N.A. Langlet in Uppsala, Sweden in 1895.
Origin : The name is derived from the Greek ‘helios’,sun.
Description :A colourless, odourless gas that is totally unreactive. It is extracted from natural gas wells, some of which contain gas that is 7% helium. It is used in deep sea diving for balloons and, as liquid helium, for low temperature research. The Earth’s atmosphere contains 5 parts per million by volume, totalling 400 million tons, but it is not worth extracting it from this source at present.
Atomic No:2 MAss No:4
Why do copper products change color, and what is the name of the process?
Probably, every person wants to know, why over time the copper turns green and becomes bloomed. This is easy to explain: that film is called patina.
Protein Design: Automated protein discovery and synthesis
In this paper I describe (theoretically) the method(s) of automated protein discovery and synthesis.
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...
Use of diamonds
Diamond is a crystalline modification of pure carbon formed in the deep interior of the Earth, in the upper mantle at depths of more than 80-100 kilometers, at exceptionally high pressure and temperature. It is the most precious stone, the hardest and most wear-resistant mineral, the most...
Redox reactions in which the oxidizing agent and the reducing agent are the same species.
A gas or mixture of gases having, in a container an absolute pressure exceeding 40 psi at 21.1°C (70°F)
An aliphatic acid, many can obtained from animal fats.
Equilibrium constant for the ionization of a weak electrolyte.
Description of the quantitative relationships among elements and compounds as they undergo chemical changes.
Adverse health effects resulting from skin exposure ot a substance.
A favourable interaction of two electrons with opposite m , values in the same orbital.
A protein that acts as a catalyst in biological systems.
Most of the microscopes used today are compound. A compound microscope features two or more lenses. A hollow cylinder called the tube connects the two lenses.
The top lens, the one people look through, is called the eyepiece. The bottom lens is known as the objective lens. Below the two lenses is the stage, with the illuminator below that.
Compound in which an oxygen atom is bonded to two alkyl or two aryl groups, or one alkyl and one aryl group.