All other isotopes of aluminium are radioactive. By far the most steady of those is 26Al, having a half-lifetime of 717,000 yrs: even though it had been present together with steady 27Al in the interstellar medium from which the Photo voltaic Technique shaped (imagine to have been made by stellar nucleosynthesis https://aluminiumgreenhouse78900.develop-blog.com/45014148/the-ultimate-guide-to-aluminium-greenhouse