Khamis, 16 Februari 2012

Acid

An acid is something that has a pH less than 7.0 .
Sometimes, the abbreviation HA is used to mean an acid.
The chemistry definition of an acid is: "a substance that donates a hydrogen ion (H+) to another substance, which is called a base. (Or give out hydrogen ions when dissolved in water.)"
Acids can be commonly found in nature. Some of these include:
Some acids are strong and others are weak. The weak acids hold on to some of their protons, while the strong acids let go of all of them. Weak acids generally have a pH value of 4-6 while strong acids have a pH value of 1-3.

source : wikipedia

Jumaat, 10 Februari 2012

5 Words

1 . explain   to give your reason for something, to make something clear
2.  eternity   never-ending period of time (noun)
3.  etiquette   correct way of behaving in society
4.  evasion   avoiding
5.  exemplify   to show as an example, to be an example

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