Why do you think it is difficult for scientist's to clearly classify element's as metals, nonmetals, or metalloids?

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

How many moles in .5g of sodium bromide?

Agas has an empirical formula ch4. 0.16g of the gas occupies a volume of 240cm^3 what is the molecular formula of the me anyone who !