Which chemical equation represents a physical change? 2CH3OH(l) + 3O2(g) --> 2CO2(s) + 4H2O(g)

2H2(g) + O2(g) --> 2H2O(g)

NaCl(aq) --> H2O(g) + NaCl(s)

2Li(s) + 2H2O(l) --> 2LiOH(s) + H2(g)

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Which two scientific disciplines are bridged by pharmaceutical drugs? chemistry and forensics chemistry and medicine biology and forensics biology and criminology

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.