What is a vertical column of elements on the periodic table with similar properties?
The horizontal column is called a “period”. e.g, period 1, has the element Hydrogen to Helium from left to right of the periodic table, Whereas period 7, has the elements Francium, Radium, Actinium, Rutherfordium, dubnium, Seaborgium, Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium, Ununbium, Ununtrium, Ununquadium, Ununpentium, Ununhexium, Ununseptium and Ununoctium, from left to right of the periodic table!