How can you be sure a solid is pure?

Consider the elements bromine and chlorine; which elements has a larger ionic radius ?

There is one girl i like and i don't know how to tell her that, i have a feeling she knows but if she doesn't i don't want to make a fool out of myself how is one way to boost my confidence on asking her out

He nucleus contains the cells genetic material in the form of dna. dna is organized into our chromosomes, which are made up of thousands of that determine our traits.