This a very interesting visual. One would probably not consider these "small"spheres as accurate representations of the volume of water and air that exists on our planet, but according to Dan Phiffer, the spheres are accurate…
Dan Phiffer found this image on a message board, and by his calculations, he says it’s accurate.
Left: All the water in the world (1.4087 billion cubic kilometres of it) including sea water, ice, lakes, rivers, ground water, clouds, etc.
Right: All the air in the atmosphere (5140 trillion tonnes of it) gathered into a ball at sea-level density. Shown on the same scale as the Earth.