<Dl> <Dd> <Table> <Tr> <Th colspan="3"> Chemical element </Th> <Th> Chemical series </Th> <Th> Electron configuration </Th> </Tr> <Tr> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> <Th> </Th> </Tr> <Tr> <Td> 37 </Td> <Td> Rb </Td> <Td> Rubidium </Td> <Td> Alkali metal </Td> <Td> ( Kr ) 5s </Td> </Tr> <Tr> <Td> 38 </Td> <Td> Sr </Td> <Td> Strontium </Td> <Td> Alkaline earth metal </Td> <Td> ( Kr ) 5s </Td> </Tr> <Tr> <Td> 39 </Td> <Td> Y </Td> <Td> Yttrium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s </Td> </Tr> <Tr> <Td> 40 </Td> <Td> Zr </Td> <Td> Zirconium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s </Td> </Tr> <Tr> <Td> 41 </Td> <Td> Nb </Td> <Td> Niobium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s ( * ) </Td> </Tr> <Tr> <Td> 42 </Td> <Td> Mo </Td> <Td> Molybdenum </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s ( * ) </Td> </Tr> <Tr> <Td> 43 </Td> <Td> Tc </Td> <Td> Technetium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s </Td> </Tr> <Tr> <Td> 44 </Td> <Td> Ru </Td> <Td> Ruthenium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s ( * ) </Td> </Tr> <Tr> <Td> 45 </Td> <Td> Rh </Td> <Td> Rhodium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s ( * ) </Td> </Tr> <Tr> <Td> 46 </Td> <Td> Pd </Td> <Td> Palladium </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d ( * ) </Td> </Tr> <Tr> <Td> 47 </Td> <Td> Ag </Td> <Td> Silver </Td> <Td> Transition metal </Td> <Td> ( Kr ) 4d 5s ( * ) </Td> </Tr> <Tr> <Td> 48 </Td> <Td> Cd </Td> <Td> Cadmium </Td> <Td> Post-transition metal </Td> <Td> ( Kr ) 4d 5s </Td> </Tr> <Tr> <Td> 49 </Td> <Td> In </Td> <Td> Indium </Td> <Td> Post-transition metal </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> <Tr> <Td> 50 </Td> <Td> Sn </Td> <Td> Tin </Td> <Td> Post-transition metal </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> <Tr> <Td> 51 </Td> <Td> Sb </Td> <Td> Antimony </Td> <Td> Metalloid </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> <Tr> <Td> 52 </Td> <Td> Te </Td> <Td> Tellurium </Td> <Td> Metalloid </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> <Tr> <Td> 53 </Td> <Td> </Td> <Td> Iodine </Td> <Td> Reactive nonmetal </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> <Tr> <Td> 54 </Td> <Td> Xe </Td> <Td> Xenon </Td> <Td> Noble gas </Td> <Td> ( Kr ) 4d 5s 5p </Td> </Tr> </Table> </Dd> </Dl>
the atomic number of indium which belongs to 5th period is
49