Period (periodic table) Period (periodic table) A period in the periodic table is a horizontal row. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, groups of elements in the same column have similar chemical and physical properties, reflecting the periodic law. For example, the alkali metals lie in the first column (group 1) and share similar properties, such as high reactivity and the tendency to lose one electron to arrive at a noble-gas electronic configuration. As of 2016, a
The Periodic Table (short story collection) The Periodic Table (short story collection) The Periodic Table () is a collection of short stories by Primo Levi, published in 1975, named after the periodic table in chemistry. In 2006, the Royal Institution of Great Britain named it the best science book ever. The stories are autobiographical episodes of the author's experiences as a Jewish-Italian doctoral-level chemist under the Fascist regime and afterwards. They include various themes that follow a chronological sequence: his ancestry, his study of chemistry and practising the profession in wartime Italy, a pair of imaginative tales he wrote at that time, and his subsequent experiences