This number--called a mole--is a basic measuring unit in chemistry. Mole Day typically falls during National Chemistry Week. Students develop a new method of counting objects, called the PCU, and ...

The chemical formula of a covalent molecular substance gives the number of atoms per molecule. The formula of a covalent network or ionic compound gives the simplest ratio of atoms/ions in the ...

The mass of one mole of any substance is numerically equal to its relative formula mass or relative atomic mass For example, one mole of carbon is 12 g and contains 6 × 10 23 atoms of carbon.