File talk:Periodic Table Radioactivity.svg

This file in its current version seems to be extremely wrong and the description is mis-leading.

• First, the radioactivity of an element (in natural isotopic composition) is determined not by half-life of the most stable isotope, but (usually) by half-life of most instable naturally occurring isotope. For example, natural potassium is radioactive because it contains weakly radioactive K-40 (and two stable isotopes); bismuth is radioactive, too, but potassium is ~10,000,000 times more radioactive than bismuth (32 decays/s per 1 g of K, ~100 decays/year per 1 g of Bi). In the picture, however, we see that K is cyan colored, Bi is green. The Italian description of cyan cells ("Elemento con tutti gli isotopi stabili" -- "Elements with all stable isotopes") is wrong because 1) any element has radioactive isotopes, artificial and/or natural; 2) naturally occurring isotopic compositions of K, Ca, V, Ge, Se, Rb, Zr, Mo, Cd, In, Te, Ba, La, Nd, Sm, Eu, Gd, Lu, Hf, W, Re, Os, Pt contains at least one radioactive long-lived isotope but marked here as cyan-colored.

• Second, the description of green cells ("Radioactive elements with isotopes with very long decay half-times. Their half-life of over a million years gives them very small or negligible radioactivities and thus may be handled without any precautions."). Good claim, but "without any precautions" for handling of (for example) a piece of plutonium sounds too optimistic. This claim is partially correct for long-lived Pu-244 (T1/2=80 Myr, but don't forget about chemical toxicity), however if a hypothetic reader would get literally that no precautions is need for standard reactor or bomb Pu he/she could be bad surprised.

• Third, description for yellow ("may present low health hazards") and brown ("are known to pose high safety risks") cells is again based on the most stable isotope, but the recommendations like these should be based on well-known classes of danger of radionuclides. Different isotopes of the same element have very different danger, and there is no way to place all of them in one cell.

So, the wrong information in this file is potentially dangerous and should be corrected asap. The good idea is to change the colors of the cells in agreement with natural activities of elements (for example, natural thorium is 4070 Bq/g, natural uranium is ~26000 Bq/g, see above activities of K and Bi...), and to correct the misleading descriptions, by removing any recommendations concerning radiation risks, commercial applications etc. -- all these recommendations can be related only to a radioactive isotope, not to a radioactive element. --V1adis1av (talk) 15:47, 15 August 2011 (UTC)

half life for element 110, 112, 114 should be >1 minutes.

C933103 (talk) 15:56, 3 May 2014 (UTC)

Red and orange colors too similar

I am not colorblind but on first glance the colors in the image seem much too similar to me (to the point that I was about to ask for errata). I think the color scale in the description provides a somewhat better contracts between red and orange. 2600:1700:4579:B80:C8E8:50A8:70AC:8C0 17:49, 28 December 2022 (UTC)