Blood is created in bone marrow and is made up of cells suspended in liquid plasma. Red blood cells carry oxygen, white blood cells fight infection, and platelets are cell fragments that allow blood to clot.

The crust and the rigid lithosphere (upper mantle) is made up of approximately thirty separate plates. These plates more very slowly on the slightly more liquid mantle (asthenosphere) beneath them. This movement has resulted in continental drift which is the gradual movement of land masses across Earth's surface. Continental drift is a very slow process, occurring over hundreds of millions of years.

A proton is a subatomic particle found in the nucleus of an atom. It carries a positive electric charge.

The formula to convert from F° to C° is:

\(C° = {5 \over 9} (F° - 32)\)

plugging in our values gives:

\(C° = {5 \over 9} (50 - 32)\)

\(C° = {5 \over 9} (18)\)

\(C° = {90 \over 9}\)

\(C° = 10\)

Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.