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 three main types of blood vessels: 1  arteries take blood away from the heart to the body organs and tissues. 2  capillaries are tiny, thin-walled vessels which form a network to take blood through the organsand tissues. 3  veins collect blood from the capillaries in the body and return the blood to the heart.rteries, veins and capillaries. There are three main types of blood vessels: 1  arteries take blood away from the heart to the body organs and tissues. 2  The artery wall is thick and muscular so it can withstand the high pressure of the blood being pumped directly from the heart.