Dividing line between metals and nonmetals

1	2	12	13	14	15	16	17	18
H								He
Li	Be		B	C	N	O	F	Ne
Na	Mg		Al	Si	P	S	Cl	Ar
K	Ca	Zn	Ga	Ge	As	Se	Br	Kr
Rb	Sr	Cd	In	Sn	Sb	Te	I	Xe
Cs	Ba	Hg	Tl	Pb	Bi	Po	At	Rn
Fr	Ra	Cn	Nh	Fl	Mc	Lv	Ts	Og

Condensed periodic table showing a typical metal–nonmetal dividing line. Elements commonly recognised as metalloids (boron, silicon, germanium, arsenic, antimony and tellurium) and those inconsistently recognised as such (polonium and astatine) Metal-nonmetal dividing line (arbitrary): between Li and H, Be and B, Al and Si, Ge and As, Sb and Te, Po and At, Ts and Og

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.^[1]

The location and therefore usefulness of the line is debated. It cuts through the metalloids, elements that share properties between metals and nonmetals, in an arbitrary manner, since the transition between metallic and non-metallic properties among these elements is gradual.

^ Horvath 1973, p. 336

[1] Horvath 1973, p. 336

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