<Table> <Tr> <Th_colspan="19"> (hide) <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> Period 3 in the periodic table </Th> </Tr> <Tr> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> 5 </Th> <Th> 6 </Th> <Th> 7 </Th> <Th> 8 </Th> <Th> 9 </Th> <Th> 10 </Th> <Th> 11 </Th> <Th> 12 </Th> <Th> 13 </Th> <Th> 14 </Th> <Th> 15 </Th> <Th> 16 </Th> <Th> 17 </Th> <Th> 18 </Th> </Tr> <Tr> <Th_colspan="3"> Group → </Th> </Tr> <Tr> <Th_colspan="3"> ↓ Period </Th> </Tr> <Tr> <Th> </Th> <Td> Sodium 11 Na 7001229899999999999 ♠ 22.990 </Td> <Td> Magnesium 12 Mg 7001243050000000000 ♠ 24.305 </Td> <Td_colspan="10"> </Td> <Td> Aluminium 13 Al 7001269820000000000 ♠ 26.982 </Td> <Td> Silicon 14 Si 7001280850000000000 ♠ 28.085 </Td> <Td> Phosphorus 15 P7001309740000000000 ♠ 30.974 </Td> <Td> Sulfur 16 S7001320600000000000 ♠ 32.06 </Td> <Td> Chlorine 17 Cl 7001354500000000000 ♠ 35.45 </Td> <Td> Argon 18 Ar 7001399480000000000 ♠ 39.948 </Td> </Tr> <Tr> <Td_colspan="19"> </Td> </Tr> <Tr> <Td_colspan="19"> <P> 1 (red) = Gas 3 (black) = Solid 80 (green) = Liquid 109 (gray) = Unknown Color of the atomic number shows state of matter (at 0 ° C and 1 atm) </P> Primordial From decay Synthetic Border shows natural occurrence of the element <P> Background color shows subcategory in the metal--metalloid--nonmetal trend: </P> <Table> <Tr> <Td_colspan="6"> Metal </Td> <Td> Metalloid </Td> <Td_colspan="3"> Nonmetal </Td> </Tr> <Tr> <Td> Alkali metal </Td> <Td> Alkaline earth metal </Td> <Td> Lanthanide </Td> <Td> Actinide </Td> <Td> Transition metal </Td> <Td> Post - ​ transition metal </Td> <Td> Polyatomic nonmetal </Td> <Td> Diatomic nonmetal </Td> <Td> Noble gas </Td> </Tr> </Table> </Td> </Tr> </Table> <Tr> <Th_colspan="19"> (hide) <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> Period 3 in the periodic table </Th> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <Tr> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> 5 </Th> <Th> 6 </Th> <Th> 7 </Th> <Th> 8 </Th> <Th> 9 </Th> <Th> 10 </Th> <Th> 11 </Th> <Th> 12 </Th> <Th> 13 </Th> <Th> 14 </Th> <Th> 15 </Th> <Th> 16 </Th> <Th> 17 </Th> <Th> 18 </Th> </Tr>

Where are highly reactive elements found on the periodic table