How to read the periodic table?
How to read the periodic table? To read the periodic table, start with an element's tile: the whole number is its atomic number (protons), the one- or two-letter abbreviation is its symbol, and the decimal number is its atomic mass in atomic mass units. Chemists turn to the modern periodic table for atomic weight, electron configuration and periodic trends in one view.
For carbon the tile shows 6, C and 12.011. Next use position: the column number (1 to 18) is its group, which tells you the family and valence electrons, and the row number (1 to 7) is its period, which tells you how many electron shells it has. If you are studying, you may also want the answer to “what is a period on the periodic table of elements”.
Carbon is in group 14 and period 2, so it has four valence electrons and two shells. Colors usually show the element's family or whether it is a metal, nonmetal or metalloid, with metals to the left, nonmetals to the right and metalloids along the staircase.
Some charts give more information, such as electron configuration, oxidation states, melting point or whether the element is a solid, liquid or gas, and a key helps you understand each. Here is a quick routine for any tile. Readers also ask “how to memorize a periodic table”, which has its own short answer.
First read the atomic number to know how many protons the element has. Second read the symbol and name to identify it. Third read the atomic mass to find its average mass in atomic mass units.
Fourth find the column for the group and the row for the period, and check the color or legend for the family or metal type. Using chlorine as another example, atomic number 17, symbol Cl and atomic mass 35.45, the position shows group 17 and period 3, so chlorine is a halogen with seven valence electrons that tends to gain one electron and form a −1 ion. Electron configuration shortcuts, such as [Ne] 3s2 3p5 for chlorine, can also appear on the tile.
If the tile shows a mass in brackets, such as [98] for technetium, the element is radioactive and the number refers to its most stable isotope. A key at the side explains the colors, the state of matter at room temperature and any other marks. Round the atomic mass and subtract the atomic number to estimate neutrons.