How to use the periodic table..?
How to Use the Periodic Table of Elements The table is most commonly used to look up the atomic weight of the elements. Those are used to calculate the molar mass of any compound. The molar mass of a compound is the mass in grammes of 6.022 x 1023 units of the compound (normally molecules). The number 6.022 x 1023 is also called one mole or the Avogadro3 number or more rarely the Lochschmidt number4. Example: (To illustrate the usage of moles, atomic weights and the periodic table.) For any reason a chemist needs one mole of potassium permanganate (KMnO4). She looks at the formula and calculates the weight of one mole of potassium (by checking the periodic table), one mole of manganese and four moles of oxygen (four because there are four oxygens in one unit of the permanganate). She adds the numbers and finds that she will need 158.04 grammes of the potassium permanganate (which is available as a violet, rather dangerous powder). Weighing a powder is more effective and can be done fas
