As a parcel of air rises, it will (expand or compress) and (warm or cool).

As air rises, it expands because there is less atmospheric pressure at higher altitudes. As air expands, it cools. Cool air holds less mois- ture, rain falls and the cloud loses moisture. After it passes over the mountain, it drops down in elevation and the air becomes compressed and becomes warmer.

Explanation:

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.