<Li> by isotope stability </Li> <Ul> <Li> by annual production </Li> <Li> by symbol </Li> </Ul> <Li> by annual production </Li> <Tr> <Td> Properties of elements (show) <Table> </Table> <Ul> <Li> Atomic weight </Li> <Li> Crystal structure </Li> </Ul> <Ul> <Li> Electron affinity </Li> <Li> configuration </Li> </Ul> <Ul> <Li> Electronegativity ((Allen)) ((Pauling)) </Li> </Ul> <Ul> <Li> Goldschmidt classification </Li> </Ul> <Ul> <Li> Nutrition </Li> <Li> Valence </Li> </Ul> </Td> </Tr>

How many group 17 elements are in period 3 of the periodic table