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 various kinds of blood vessels: 1  Arteries. 2  Elastic arteries. 3  Distributing arteries. 4  Arterioles. 5  Capillaries (the smallest blood vessels). 6  Venules. 7  Veins. 8  Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein.here are various kinds of blood vessels: 1  Arteries. 2  Elastic arteries. 3  Distributing arteries. 4  Arterioles. 5  Capillaries (the smallest blood vessels). 6  Venules. 7  Veins. 8  Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein.