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Glossary of Terms > E


An ecological community together with its environment, functioning as a unit.


A very sensitive long range galvanometer, often used in electomagnetic induction experiments.

EHT Unit

Stands for Extra High Tension. A high voltage power supply with a high internal resistance which means the current it supplies is low but voltage is high.


A method of separating bonded elements and compounds by passing an electric current through them.

Electromagnetic induction

The production of electricity by moving a magnet through a coil of wire.

Electromagnetic spectrum

The full range of electromagnetic radiation including ultra violet, microwaves, radio waves etc.


The electron is a fundamental subatomic particle that carries a negative electric charge and has negligible mass.


A device for detecting the presence of electric charges by means of electrostatic attraction and repulsion, often between two pieces of gold leaf enclosed in a glass-walled chamber. These are often called gold leaf electroscopes. Click here for Gold Leaf Electroscope equipment page.


One of a class of substances that cannot be separated into simpler substances by chemical means.


Proteins which accelerate (catalyze) biochemical reactions. Examples include; protease, amylase, lipase and rennin.