The two elements 11X and 19Y are in the same group because they have the same
Answer Details
The two elements 11X and 19Y are in the same group because they have the same number of valence electrons. The elements in the same group of the periodic table have similar chemical and physical properties, and this is largely due to the fact that they have the same number of valence electrons in their outermost energy level. Valence electrons are the electrons in the outermost energy level of an atom that are involved in chemical bonding with other atoms. Elements in the same group have the same number of valence electrons, which gives them similar reactivity and bonding patterns. In this case, both 11X and 19Y have the same number of valence electrons, which means that they belong to the same group of the periodic table.