Which of these are common to all mammals?

a: type of reproductive system, brain size, skin
b: digestive system, heart lungs
c: digestive system, number of toes, blood
d: kidneys, liver, skeletal structure

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car