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 3 main kinds of blood vessels â arteries, veins and capillaries. 1  Arteries carry blood away from the heart. 2  The capillaries gradually join up with one another to form large vessels called veins. 3  Veins carry blood towards the heart. 71 Arteries, veins and capillaries-structure and functions. There are 3 main kinds of blood vessels â arteries, veins and capillaries. 1  Arteries carry blood away from the heart. 2  They divide again and again, and eventually form very tiny vessels called capillaries.