| Propane | A heavy flammable gas found in crude petroleum and natural gas and used especially as fuel and in the chemical industry |
| Altitude | The height of an object in relation to sea level or ground level. |
| Fahrenheit | A unit of measurement used to measure temperature |
| Cubic feet | A common way to measure and express the volume of 3D spaces |
| Buoyant | Able to keep afloat or rise to the top of a liquid or gas. |
| Descend | Move or fall downwards. |
| Altimeter | An instrument for measuring altitude |
| Descent | The act of moving downwards, dropping, or falling |
| Principle | Ideas based on scientific rules and laws |
| Ounce | A unit of weight about approximately 28 grams. |
