III.

Uses of the Periodic Table

The periodic table is an important tool for scientists and students studying the chemical elements. If a person knows the main properties of each of the groups in the periodic table and how chemical properties vary within a group, he or she can predict the properties of any particular element with a reasonable degree of confidence. For example, if a student needs to know the properties of francium, she can predict that it, like other elements of group 1, will be a soft metal and will react even more vigorously with water than the elements above it. If another student wants to predict what compounds tellurium will form in combination with hydrogen, he can guess that the two elements will form H₂Te because the other elements in tellurium’s group form similar hydrogen compounds: H₂O, H₂S, and H₂Se.