Back to: Science e-catalog Grade 5 e-Glossary E

List of Words for Letter ‘E’

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earthquake A sudden shaking of Earth’s crust.
echolocation Finding an object by using reflected sound.
ecosystem AAll the living and nonliving things in an environment, including their interactions with each other.
efficiency The measure of how much useful work a machine puts out compared to the amount of work put into it.
effort The force applied to a machine.
electric current A flow of electricity through a conductor.
electricity The movement of electrons.
electrolyte A substance that forms ions when dissolved and that conducts electricity.
electromagnet An electric circuit that produces a magnetic field.
electromagnetism The way electric and magnetic forces interact.
electron A particle in the space outside the nucleus of an atom that carries one unit of negative electric charge.
element A pure substance that cannot be broken down into any simpler substances through chemical reactions.
El Niño A change in weather conditions caused by the sinking of the cold current in the Pacific Ocean. Higher tides, heavy rains, and storms occur along the coasts of North and South America. A developing organism that results from fertilization.
embryo A developing organism that results from fertilization.
endangered species A species that is in danger of becoming extinct.
endocrine system The set of ductless organs that secrete hormones directly into the bloodstream to regulate life processes.
energy The ability to perform work or change an object.
energy pyramid A diagram that shows the amount of energy available at each level of an ecosystem.
epicenter The point on Earth’s surface directly above the focus of an earthquake.
era stretches of time used to measure Earth’s geological history.
erosion The process of carrying away soil or pieces of rocks.
estuary The boundary where a freshwater ecosystem meets a saltwater ecosystem.
evaporation The change of a liquid into a gas below the boiling point.
excretory system The organ system that removes cellular wastes from the body.
external fertilization The process in which sperm and egg cells come together outside the female’s body.
extinct species A species that has died out completely.