Posts Tagged ‘chemistry trivia’

Chemical Compound Facts

by admin on Saturday, March 13, 2010 18:12 under Interesting Facts.

Compounds are substances that are made when the atoms of two or more different elements join together.
The properties of a compound are usually very different from those of the elements which it is made of.
Compounds are different from mixtures because the elements are joined together chemically. They can only be separated by a chemical reaction.
Every molecule of a compound is exactly the same combination of atoms.
The scientific name of a compound is usually a combination of the elements involved, although it might have a different common name.
Table salt is the chemical compound sodium chloride. Each molecule has one sodium and one chlorine atom.
The chemical formula of a compound summarizes which atoms a molecule is made of. The chemical formula for water is H 20 because each water molecule has two hydrogen (H) atoms and one oxygen (0) atom.
Table salt, or sodium chloride, forms when sodium Hydroxide neutralizes hydrocloric acid.
There only 100 or so elements but they can combine in different ways to form many millions of compounds.
The same combination of elements, such as carbon and hydrogen, can form many different compounds.
Compounds are either organic (see organic chemistry), which means they contain carbon atoms, or inorganic.

by admin on Saturday, March 13, 2010 18:10 under Interesting Facts.

Chemical bonds link together atoms to make molecules (see molecules).
Atoms can bond in three main ways: ionic bonds, covalent bonds and metallic bonds.
In ionic bonds electrons are transferred between atoms.
Ionic bonds occur when atoms with just a few electrons in their outer shell give the electrons to atoms with just a few missing from their outer shell.
An atom that loses an electron becomes positively charged; an atom that gains an electron becomes negatively charged so the two atoms are drawn together by the electrical attraction of opposites.
Sodium loses an electron and chlorine gains one to form the ionic bond of sodium chloride (table salt) molecules.
In covalent bonding, the atoms in a molecule share electrons.
Because they are negatively charged, the shared electrons are drawn equally to the positive nucleus of both atoms involved. The atoms are held together by the attraction between each nucleus and the shared electrons.
In metallic bonds huge numbers of atoms lose their electrons. They are held together in a lattice by the attraction between ‘free’ electrons and positive nuclei.