Dividing line between metals and nonmetals

||1|2||12|13|14|15|16|17|18||||||||||||
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
||style="border-right:1px solid black; border-top:1px solid black; border-left:1px solid black; border-bottom:2px solid grey;"|<big>H</big>|style="border-right:0px; border-top:0px; border-left:0px; border-bottom:2px solid grey"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:0px solid black"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:0px solid black"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:1px solid black"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:1px solid black"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:1px solid black"||style="border-right:0px; border-top:0px; border-left:0px; border-bottom:1px solid black"||style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"||style="border-right:1px solid black; border-top:1px solid black; border-left:0px; border-bottom:1px solid black"|<big>He</big>||
||style="border-right:1px solid black; border-top:2px solid grey; border-left:1px solid black; border-bottom:1px solid black"|<big>Li</big>|style="border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Be</big>|style="border-left:2px solid grey"||style="border-right:2px solid grey; border-top:0px; border-left:0px; border-bottom:0px solid black"||style="color:#000000; border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:2px solid grey"|<big>B</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>C</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>N</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>O</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>F</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ne</big>||
||style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Na</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Mg</big>||style="border-right:1px solid black; border-bottom:1px solid black"||style="border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Al</big>|style="color:#000000; border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:2px solid grey"|<big>Si</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>P</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>S</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Cl</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ar</big>|||
||style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>K</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ca</big>|...|style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Zn</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ga</big>|style="color:#000000; border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Ge</big>|style="color:#000000; border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:2px solid grey"|<big>As</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Se</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Br</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Kr</big>|||
||style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Rb</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Sr</big>|...|style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Cd</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>In</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Sn</big>|style="color:#000000; border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Sb</big>|style="color:#000000; border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:2px solid grey"|<big>Te</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>I</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Xe</big>|||
||style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Cs</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ba</big>|...|style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Hg</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Tl</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Pb</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Bi</big>|style="color:#000000; border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Po</big>|style="color:#000000; border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:2px solid grey"|<big>At</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Rn</big>|||
||style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Fr</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Ra</big>|...|style="border-right:1px solid black; border-top:0px; border-left:1px solid black; border-bottom:1px solid black"|<big>Cn</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Nh</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Fl</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Mc</big>|style="border-right:1px solid black; border-top:0px; border-left:0px; border-bottom:1px solid black"|<big>Lv</big>|style="border-right:2px solid grey; border-top:2px solid grey; border-left:0px; border-bottom:1px solid black"|<big>Ts</big>|style="border-right:1px solid black; border-top:0px; border-left:2px solid grey; border-bottom:1px solid black"|<big>Og</big>|||
||colspan="10" style="text-align:left; font-size:90%"|An example of a periodic table   dividing line, shown in the _s_- and _p_-blocks.||||||||||||||||||||

The **dividing line between metals and nonmetals** is a stair-shaped line on the periodic table which separates chemical elements into metals and nonmetals.

There is no formal definition of "metal" in chemistry. This line is a convention, and not a firm scientific rule. Most of the elements close to the line are called metalloids, because they have some things in common with metals and other things with nonmetals.