Question Number 17918 by Tinkutara last updated on 12/Jul/17
$$\mathrm{Write}\:\mathrm{the}\:\mathrm{electronic}\:\mathrm{configuration}\:\mathrm{and} \\ $$$$\mathrm{the}\:\mathrm{block}\:\mathrm{to}\:\mathrm{which}\:\mathrm{an}\:\mathrm{element}\:\mathrm{with} \\ $$$$\mathrm{Z}\:=\:\mathrm{90}\:\mathrm{belongs}. \\ $$