Elements in the same group are most similar.
The elements in the same families (columns) are the most similar.
I expect elements with similar properties in the periodic table to be most similar. For example, elements in the same group or period tend to have similar chemical characteristics due to their similar electron configurations.
In the periodic table, the elements are grouped according to their properties. Elements in a group has an equal number of valence electrons. So the elements in a group have most common chemical properties.
Zinc is similar to cadmium and magnesium.
Strontium is the element most similar in behavior to calcium due to being in the same group (group 2) of the periodic table. Both elements share similar chemical properties such as forming divalent cations and reacting with water and acids in a similar manner.
Rb
Buttholes
1 and 2
Fluorine is similar to chlorine.
Aluminum and silicon are elements that likely have physical and chemical properties most similar to boron. They are in the same group as boron on the periodic table and share some similar characteristics in terms of reactivity and bonding.
Calcium (Ca) and magnesium (Mg) are the most similar elements, as they both belong to Group 2 of the periodic table and have similar chemical properties due to their valence electron configuration. Both elements are soft, silvery-white metals that react with water and oxygen to form oxide compounds.
The most important principle was the listing in groups, after similar chemical or physical properties.