APA citation style: Historic American Buildings Survey, C. & Benison, G. (1933) Oakland Plantation, Mount Pleasant, Charleston County, SC. Documentation Compiled After. [Pdf] Retrieved from the Library of Congress, https://www.loc.gov/item/sc0292/.
There are 18 groups (columns) in the periodic table. Group 1 (also known as the alkali metals) is the column on the far left of the table. Elements in the same group have similar, but not identical characteristics. This is because they all have the same number of electrons in their outermost shell.
The Periodic Table is an arrangement of the elements in order of atomic number. Columns in the table - groups. The elements in any one vertical column are said to be in the same group or family. Eight of the groups are numbered from left to right. Elements in the same group have similar chemical properties. The group number is the same as the number of electrons in the outer shell of all the elements in the group.