Kidneys are a filter system. The main job of the kidneys is to remove waste from the blood and return the cleaned blood back to the body. Each minute about one litre of blood ï­ one-fifth of all the blood pumped by the heart - enters the kidneys through the renal arteries.
The volume of helium in the balloon has been estimated as being able to lift a total load, including the balloon material and the structure beneath it, of 65 pounds (29 kg) at sea level and 48 pounds (22 kg) at 8,000 feet (2,400 m).
Balloons filled with helium only float in our atmosphere because the average density of the gas and the balloon itself is less than that of the atmosphere around it. An easy way to show this is to try and put a blown up balloon underwater-the density of the water forces the balloon to rise to the surface. balloon expands to a certain level until the gas inside it is at an equal level of pressure with the gas outside, E.G: There are the same number of atoms bouncing off the inside of the balloon as there are bouncing off the outside, forming a balance of forces.