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frog

(Encyclopedia)frog, common name for an amphibian of the order Anura. Frogs are found all over the world, except in Antarctica. They require moisture and usually live in quiet freshwater or in the woods. Some frogs ...

wave, in the earth sciences

(Encyclopedia)CE5 A. Diagram of wave: Wave travels one wavelength during one period B. Diagram of wave: Phase relationships wave, in oceanography, an oscillating movement up and down, of a body of water caused ...

fog

(Encyclopedia)fog, aggregation of water droplets or ice crystals immediately above the surface of the earth (i.e., a cloud near the ground). A light or thin fog is usually called a mist. Fog may occur when the mois...

chemical equation

(Encyclopedia)chemical equation, group of symbols representing a chemical reaction. There are a number of other symbols used in chemical equations. A symbol written above or below the reaction arrow indicates spe...

antidiuretic hormone

(Encyclopedia)antidiuretic hormone ănˌtēdīyo͞orĕtˈĭk [key], polypeptide hormone secreted by the posterior pituitary gland. Its principal action is to regulate the amount of water excreted by the kidneys. An...

bromide

(Encyclopedia)bromide, any of a group of compounds that contain bromine and a more electropositive element or radical. Bromides are formed by the reaction of bromine or a bromide with another substance; they are wi...

ethanol

(Encyclopedia)ethanol ĕthˈənōlˌ [key] or ethyl alcohol, CH3CH2OH, a colorless liquid with characteristic odor and taste; commonly called grain alcohol or simply alcohol. Ethanol is used extensively as a solv...

formula weight

(Encyclopedia)formula weight, in chemistry, a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a formula by the number of atoms of that element present in the formula, an...

hydroplane

(Encyclopedia)hydroplane, small, high-powered racing boat designed to skim along the surface of the water. Its hull is so shaped that at high speeds the bow is tilted up out of the water, reducing the effect of fri...

pump

(Encyclopedia)pump, device to lift, transfer, or increase the pressure of a fluid (gas or liquid) or to create a vacuum in an enclosed space by the removal of a gas (see vacuum pumps under vacuum). The centrifugal ...