<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The dividing line between metals and nonmetals can be found, in varying configurations, on some representations of the periodic table of the elements (see mini-example, right). Elements to the lower left of the line generally display increasing metallic behaviour; elements to the upper right display increasing nonmetallic behaviour . When presented as a regular stair - step, elements with the highest critical temperature for their groups (Li, Be, Al, Ge, Sb, Po) lie just below the line . </P> <P> This line has been called the amphoteric line, the metal - nonmetal line, the metalloid line, the semimetal line, or the staircase . It is also erroneously referred to as the Zintl border or the Zintl line . The last two terms instead refer to a vertical line sometimes drawn between groups 13 and 14 . This particular line was christened by Laves in 1941 . It differentiates group 13 elements from those in and to the right of group 14 . The former generally combine with electropositive metals to make intermetallic compounds whereas the latter usually form salt - like compounds . </P>

What is the zig zag line in the periodic table