the best chemistry links

 

I’ve chosen to share some very interesting web links. I think everybody working on a subject needs of small guides to advance or just to understand something well. So, don’t be stop by a chemistry abbreviation or small other thinks ans just click on the appropriate link before make all the websites !

Spectra data base for organic compounds:

http://sdbs.db.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng

The basic of NMR by Dr. Joseph P. Hornak:

http://www.cis.rit.edu/htbooks/nmr/

Named reagents: just click on a name or abbreviation and you will have the corresponding structure :

http://www.chem.wisc.edu/areas/reich/handouts/NameReagents/namedreag-cont.htm

A virtual museum of mineral and molecules:

http://virtual-museum.soils.wisc.edu/displays.html

Chemistry glossary:

http://chemistry.about.com/od/chemistryglossary/a/glossarya.htm

Enjoy!

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What’s good to be a chemist

The work of a chemist is everyday a challenge, exciting when you find something new, sometimes stressful but rewarding. Having a chemistry degree in hand can open many doors such as:

Academic Institutions

You might work as a teacher at the university or in high school, teacher in primary or secondary school, or researcher in a university or industry.

Federal, State, and Local Government Agencies

  1. Drug Administration as a medicinal, analytical or biochemical chemist
  2. Department of Justice and other law enforcement agencies or analytical chemist
  3. Department of Agriculture as an agricultural, biochemical, Environmental, or analytical chemist
  4. Environmental Protection Agency, environmental, inorganic or organic chemist
  5. Patent Office as a patent researcher or lawyer
  6. National Science Foundation as a science writer and editor
  7. Department of Energy as an industrial and engineering, materials, or environmental chemist

Chemical Industries

Chemists produce everything from plastics and paints to pharmaceuticals products, flavors, fragrances, detergents, cosmetics, …

Business

Some chemists also work as business owners, consultants, art conservators, or even investment bankers.

Gravitational waves explained

A very good video about explanation of gravitational waves

https://www.youtube.com/watch?v=4GbWfNHtHRg

What are gravitational waves?

Colossal cosmic collisions and stellar explosions can rattle spacetime itself. Relativity rule predicts that ripples in the fabric of space-time radiate energy . After some time, they reach Earth, compress spacetime by as little as one ten-thousandth, the width of a proton.

How are they detected?

To spot a signal, LIGO uses a special mirror to split a beam of laser light and sends it down two 4-kilometer-long arms, at a 90 degree angle to each other. After ricocheting back and forth 400 times, turning each beam’s journey into a 1,600 kilometer round-trip, the light recombines near its source.

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flame test for the determination of metals or ions

Flame tests are used in chemistry to identify metals or ions in compounds. They are more useful for some metals than others; particularly for the Group 1 metals, they provide a good way of quickly identifying the metal ion present.

This picture looks at the colour of various metal and metalloid ions that occur during flame tests. Most people probably remember have seen one flame test (often sodium) during an experiment in  experimental lesson at school.Metal-Ion-Flame-Test-Colours-Jan-15-724x1024

To carry out the flame tests, a small amount of the compound being tested will be held in a flame and the colour given off observed. This colour originates from the movement of the electrons in metal ion. When heated, the electrons gain energy, and are « excited » into higher energy levels; however, the electrons occupying these levels is more energetically unstable, and they tend to fall back down to their original energy levels, releasing energy as they do so. This energy is released as light, with the characteristic flame colours of different metal ions due to varying electron transitions.

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Chemical actions of love on the brain !

“Love looks not with the eyes, but with the mind,” as Shakespeare’s Helena said and  neuroscientists would agree.

Love might seem to move in mysterious ways, but scientists actually have a pretty good idea of what love does to the brain. Being in love floods the brain with chemicals and hormones that produce feelings of pleasure, obsession and attachment.

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This funny little video shows you the chemical effects of love somebody on your body. And unfortunately the  chemical effects of a rupture …

In fact, your body is regulated such as a machine !! But this animation explains this with humor ..don’t be worry

https://www.facebook.com/IFeakingLoveScience/videos/1320720811282260/

 

Dynamic Periodic Table

On this Periodic Table  (link in end of my text), you have access on one click to the description of the elements, for example if you click on Co you have directly the cobalt wikipedia page which opens.

There are also the properties of each elements, just click on one, and you have access to the state of this element at 273 K, the melting point, boiling point, electronegativity, valence, …….

The bottom orbitals shows you the quantic cases with the spin. You have in the same way: n, m and l. And the representation of s, p,d and f orbitals corresponding to the element chosen.

Isotopes is an access to all isotopes for one element you have chosen.

And to finish Compounds permits you to have a list of compounds containing the element you have chosen.

http://www.ptable.com/?lang=en#Writeup/Wikipedia

Size exclusion chromatography

Size Exclusion Chromatography (SEC) consists on the separation technique based on the molecular size of the components, used for semi-preparative purifications and various analytical assays. It is a separation technique which takes the advantage of the difference in size of the molecules. separation is achieved by the differential exclusion from the pores of the packing material, of the sample molecules as they pass through a bed of porous particles. The principle feature of SEC is its gentle non-adsorptive interaction with the sample, enabling high retention of biomolecular activity.

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 Principe

Size exclusion chromatography (SEC) is the separation of a mixture based on the molecular size of the components in this mixture. The separation is achieved by the differential exclusion or inclusion of solutes as they pass through stationary phase consisting of pores of different sizes cross linked polymeric gels or beads. The process is based upon different permeation rates of each solute molecule into the interior of gel particles. Size exclusion chromatography involves gentle interaction with the sample, enabling high retention of biomolecular activity. The separation of organic polymers in non-aqueous systems is called gel permeation chromatography (GPC).

A column of  porous matrix is in equilibrium with a suitable mobile phase for the molecules to be separated. Large molecules are excluded from the pores will pass through the space  between the matrix and will come first in the effluent. Smaller molecules will get distributed in between the mobile phase of in and outside the molecular sieve and will then pass through the column at a slower rate,so appear later in effluent.

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