Which of these is true about pure substances?

a) they can only contain one type of atom
b) they may contain one type of atom or one type of molecule
c) they can contain different types of atoms and molecules
d) they can contain only one type of molecule

If 200.0g of copper(ll) sulfate react with an excess of zinc metal, what is the theoretical yield of copper

Express the following number in scientific notation. 0.026890 =

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.