| Term | Definition | | Epidemic | The occurrence of disease within a specific geographical area or population in excess of what is normally expected. |
| Etiology | The cause of. |
| Evaporation | The process by which water changes from a liquid to a gas or vapor. |
| Evolution | Evolution is the change in heritable characteristics of biological populations over successive generations, driven by mechanisms like natural selection, mutation, and genetic drift. It explains the diversity of life on Earth, proposing that all species share a common ancestor and change through "descent with modification". |
| Extraneous Variable | Extra variables (not independent, dependent, or control variables) that might influence an experiment but are not accounted for or measured or are beyond control. |
| Fake / Corrupt Experts | Relying on unqualified individuals or those with conflicts of interest to cast doubt on legitimate scientific consensus. |
| Feedback Mechanisms | Factors which increase or amplify (positive feedback) or decrease (negative feedback) the rate of a process. An example of positive climatic feedback is the ice-albedo feedback. |
| Fluorocarbons | Carbon-fluorine compounds that often contain other elements such as hydrogen, chlorine, or bromine. |
| Fossil Fuel | A general term for organic materials formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of millions of years. |
| Gene | The unit of heredity transmitted from generation to generation during sexual or asexual reproduction. More generally, the term is used in relation to the transmission and inheritance of particular identifiable traits. The simplest gene consists of a segment of nucleic acid that encodes an individual protein or RNA. |
