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Ion Tacu
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collins English Dictionary
The ''Collins English Dictionary'' is a printed and online dictionary of English. It is published by HarperCollins in Glasgow. The edition of the dictionary in 1979 with Patrick Hanks as editor and Laurence Urdang as editorial director, was the first British English dictionary to be typeset from the output from a computer database in a specified format. This meant that every aspect of an entry was handled by a different editor using different forms or templates. Once all the entries for an entry had been assembled, they were passed on to be keyed into the slowly assembled dictionary database which was completed for the typesetting of the first edition. In a later edition, they increasingly used the Bank of English established by John Sinclair at COBUILD to provide typical citations rather than examples composed by the lexicographer. Editions The current edition is the 13th edition, which was published in November 2018. The previous edition was the 12th edition, which was pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
