Which gas phase atom has no unpaired electrons in its ground state?

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.

Based on its chemical properties, identify the position of each chemical family on the periodic table.

Areaction is first order with respect to reactant x and second order with respect to reactant y. which statement describes the rate law for this reaction?