Search Results for: Ark shells not in shell
are – u, be, in,au, pt.
(iv) demerits of mendeleev's periodic table - (a) position of hydrogen - hydrogen resembles both, the alkali metals (ia) and the halogens (viia) in properties so mendeleev could not decide where to place it....
https://www.bansal.ac.in/acc_sample_ioc.pdf