The Inert Gases in Group 18 (0) (exc. Radon) are highly unreactive. They react with almost no other elements in the Periodic Table. Radon is however radioactive.
The other elements of the actinides group.
So-called NON-transition metals is not a defined group of elements, other than "All other elements that are NOT transition elements".
The valence of an element in a chemical compound can be determined by looking at the group number of the element on the periodic table. The group number indicates the number of valence electrons an element has. For example, elements in group 1 have a valence of 1, elements in group 2 have a valence of 2, and so on. The valence of an element is important in understanding how it will react with other elements to form compounds.
Almost every other element except the elements in group 18 bond with oxygen to form compounds.
The Halogens. Other elements in this group are Fluorine, Chlorine, Bromine and Astatine.
All of them tend not to react with each other until you get lower down the group
Boron is the only element in group 13 that is a metalloid, meaning it shares properties of both metals and nonmetals. It has a unique structure due to its small atomic size and high ionization energy compared to its group members. Boron also forms covalent compounds instead of ionic compounds like other group 13 elements.
Hydrogen is smaller in size compared to other elements in Group 1 because it has only one electron and a smaller atomic radius than the rest of the elements in that group.
An ELEMENT can not be separated into other elements.
The other elements relate to fluorine are chlorine, bromine , iodine etc since they have 7 valence electrons and hence, belong to group 17
Krypton and the other elements in group 18 comprise the noble gases. See links below.
The term that describes how likely an element is to form bonds with other elements is "reactivity." Reactivity depends on an element's electron configuration and its tendency to gain, lose, or share electrons with other atoms. Elements with similar reactivity often group together in the periodic table, such as the alkali metals and halogens.