According to the Bohr model, the wavelength of the light emitted by a hydrogen atom when the electron falls from a high energy (n = 4) orbit into a lower energy (n = 2) orbit.
A network of arteries and veins also carry blood throughout the body: Arteries transport blood from the heart to the body tissues. Veins carry blood back to the heart.ow the heart works. The heart is a large, muscular organ that pumps blood filled with oxygen and nutrients through the blood vessels to the body tissues. It's made up of: Four chambers. The two upper chambers, the atria, receive and collect blood.
There are two types of blood vessels: arteries and veins. Arteries carry blood under high pressure out to all areas of the body after being pumped by the heart. Veins carry blood that should be under low pressure, on its way back to the heart. An artery does not usually connect directly to a vein.Usually there are very small blood vessels called capillaries that connect an artery to a vein.. Source(s): http://www.hht.org/web/what_is_hht/overv...ere the blood in the capillaries gives oxygen to the cells and picks up the waste gas, carbon dioxide, from the cells. The capillaries are connected to the smallest veins in the body. The veins get bigger and bigger as they carry the blood back towards the heart.