2007-02-23 08:35:31 · 2 answers · asked by ? 1 in Science & Mathematics ➔ Chemistry
An element has only one kind of atom. There are 92 naturally occurring elements and about 20 man made elements. Thy have a symbol.
Ex: oxygen O, carbon C, Hydrogen H, Helium He, iron Fe, gold Au, silver Ag, neon Ne, sodium Na, Chlorine Cl.
A compound has 2 or more elements chemically combined in an exact ratio. It can only be separated by a chemical change.They have a formula.
Ex: water H2O, carbon dioxide CO2, rust FeO , sodium chloride NaCl
A mixture is a goup of things that are mixed together, not chemically combined, they are in any ratio. There is no formula because we do not know how much of each part.
Ex: dirt, salt water, air, salad, cloth, milk, any solution
Elements and compounds are considered substances because we know exactly what they are.
2007-02-23 08:58:00 · answer #1 · answered by science teacher 7 · 0⤊ 0⤋
Well, matter is anything that takes up space and can be either a solid, liquid or a gas. The elements in the periodic table have different characteristics. Th first half of the table is metals, the second half is gases and metalloids and halogens. Maybe this might give you some information you could use:http://en.wikipedia.org/wiki/Phases_of_matter
http://en.wikipedia.org/wiki/Periodic_table
2007-02-23 09:00:28 · answer #2 · answered by julie_ramrattan2003 3 · 0⤊ 0⤋