نوفمبر 5th, 2018

 

Base

Base (chemistry) In the Brensted- Lowry classification, any chemical species, ionic or molecular, capable of accepting or receiving a proton {hydrogen ion) from another substance. The other substance acts as an acid in giving up the proton. A substance may act as a base, then, only in the presence of an acid. The greater the ten­dency to accept a proton, the stronger the base. The hydroxyl ion acts…

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Barium

Barium A chemical element, Ba, with atomic number 56 and atomic weight of 137.34. Barium is eighteenth in abundance in the Earth’s crust, where it is found to the extent of 0.04%, making it intermediate in amount between calcium and strontium, the other alkaline-earth metals. Barium compounds are obtained from the mining and conversion of two barium minerals. Barite, barium sulfate, is the principal ore and contains 65.79%…

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Balance

Balance An instrument used for the precise measurement of small weights or masses in amounts ranging from micrograms up to a few kilograms.

Balances are differentiated according to design, weighing principle, and metrological criteria . For a given weighing task, a balance is selected primarily for its maximum weighing load (Max) and for the finest graduation or division (d) of its weight-reading device (scale…

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