This is easy for elements which exist as atoms.One mole of calcium has a mass of 40 g.One mole of magnesium has a mass of 24 g,.For example, look up the relative atomic mass of sodium (Na), (the larger number above it in the periodic table).Just as one mole of carbon atoms has a mass of 12 g, so the mass of one mole of the atoms of any element is its "relative atomic mass" in grams.The relative atomic mass, which can be written as Ar or RAM, is the number just above the element in the periodic table So, one mole of carbon atoms has a mass of 12 grams. In the above definition, 12 is the mass number of carbon. The number is called Avogadro's number.A mole is defined as the number of atoms in exactly 12 grams of 12C (carbon twelve). Needless to say, chemists are concerned with atoms, ions, molecules and compounds.In the same way that you can have a dozen atoms, or cars, or apples, so you can also have a mole of atoms, or cars, or apples. It is a very very big number (6 followed by 23 zeros).This number is also called Avogadro's number.Like the word "dozen" represents the number 12, so "mole" represents the number 6 x 10 23. A mole is a word which represents a number.Relative Formula Mass (R.F.M) of a Compound.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |