If the periodic table were a city, the s-block would be a small neighborhood filled with extremely similar houses and properties. read more
Within the periodic table, the s-block is located to the far left and includes all of the elements in the first two columns (columns 1 and 2) plus helium, which is located in the top right corner in column 8A (column 18 on some versions of the periodic table). read more
All of the s-block elements are unified by the fact that their valence electrons (outermost electrons) are in an s orbital. The s orbital is spherical and can be occupied by a maximum of two electrons. Elements in column 1 have one electron in the s orbital, and elements in column 2 (plus helium) have two electrons in the s orbital. read more
Some highly reactive elements are fluorine, sodium, potassium, lithium and oxygen. Reactive elements release great quantities of energy when they combine with other elements. Some tarnish in air or explode in water. read more