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 a chart of elements arranged into rows and columns (periods and groups) according to their physical and chemical properties. What is the definition of atomic number? The number of protons in the nucleus of an atom.