Atomic weights of 10 elements on periodic table about to make an historic change

Eureka Alert ^ | 15 Dec 2010 | Leanne Yohemas

[smokingfrog]

For the first time in history, a change will be made to the atomic weights of some elements listed on the Periodic table of the chemical elements posted on walls of chemistry classrooms and on the inside covers of chemistry textbooks worldwide.

The new table, outlined in a report released this month, will express atomic weights of 10 elements - hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine and thallium - in a new manner that will reflect more accurately how these elements are found in nature.

"For more than a century and a half, many were taught to use standard atomic weights — a single value — found on the inside cover of chemistry textbooks and on the periodic table of the elements. As technology improved, we have discovered that the numbers on our chart are not as static as we have previously believed," says Dr. Michael Wieser, an associate professor at the University of Calgary, who serves as secretary of the International Union of Pure and Applied Chemistry's (IUPAC) Commission on Isotopic Abundances and Atomic Weights. This organization oversees the evaluation and dissemination of atomic-weight values.

Modern analytical techniques can measure the atomic weight of many elements precisely, and these small variations in an element's atomic weight are important in research and industry. For example, precise measurements of the abundances of isotopes of carbon can be used to determine purity and source of food, such as vanilla and honey. Isotopic measurements of nitrogen, chlorine and other elements are used for tracing pollutants in streams and groundwater. In sports doping investigations, performance-enhancing testosterone can be identified in the human body because the atomic weight of carbon in natural human testosterone is higher than that in pharmaceutical testosterone.

[Hoodat]

In your 'answer', you stated this: I keep the concentration in the standard solution the same. How do you accurately know what the concentration of the standard you are using is?

[Hoodat]

Let me try again. Let's suppose your standard acid solution is 1.0 M HCl_(aq). How would you go about preparing that standard 1.0 M solution?

[allmendream]

That had to be one of the funniest things I had ever seen written here at FR.

Nobody is quite the fool like someone who thinks they know what they are talking about but does not.

The atomic mass of CL is 35.453 because it is a mix of isotopes.

The atomic mass of an electron is 0.0005, not 0.453. Gee only off by a factor of 1,000!

Wow! THE STUPID IT BURNS US, IT BITES, IT FREEZES!!!!

[virgil]

Just be sure to keep zero in its place. It can be pretty subversive. I don’t trust people who believe in nothing.

[Hoodat]

You would think by now that someone would come clean and admit that they have no clue what they are talking about, but it looks like denial is strong in this one.

[allmendream]

Know what you are talking about you do.

The fail is strong with this one.

[cavador]

Ok-Fill one balloon with co2 and fill another with oxygen and let them go.Which one will fall?-the co2 will because it is one part carbon and 2 parts oxygen.
I’m tired of companies portraying carbon dioxide filled balloons floating up to the ceiling and they shouldn’t be allowed to get away with this blatant false advertising.