<Tr> <Td_colspan="2"> IUPAC group </Td> <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> <Td_colspan="2"> Mendeleev (I--VIII) </Td> <Td> IA </Td> <Td> II A </Td> <Td> III B </Td> <Td> </Td> <Td> IV B </Td> <Td> VB </Td> <Td> VI B </Td> <Td> VII B </Td> <Td_colspan="3"> VIII B </Td> <Td> IB </Td> <Td> II B </Td> <Td> III B </Td> <Td> IV B </Td> <Td> VB </Td> <Td> VI B </Td> <Td> VII B </Td> <Td> </Td> </Tr> <Tr> <Td_colspan="2"> CAS (US, A-B-A) </Td> <Td> IA </Td> <Td> IIA </Td> <Td> IIIB </Td> <Td> </Td> <Td> IVB </Td> <Td> VB </Td> <Td> VIB </Td> <Td> VIIB </Td> <Td_colspan="3"> VIIIB </Td> <Td> IB </Td> <Td> IIB </Td> <Td> IIIA </Td> <Td> IVA </Td> <Td> VA </Td> <Td> VIA </Td> <Td> VIIA </Td> <Td> VIIIA </Td> </Tr> <Tr> <Td_colspan="2"> old IUPAC (Europe, A-B) </Td> <Td> IA </Td> <Td> IIA </Td> <Td> IIIA </Td> <Td> </Td> <Td> IVA </Td> <Td> VA </Td> <Td> VIA </Td> <Td> VIIA </Td> <Td_colspan="3"> VIII B </Td> <Td> IB </Td> <Td> IIB </Td> <Td> IIIB </Td> <Td> IVB </Td> <Td> VB </Td> <Td> VIB </Td> <Td> VIIB </Td> <Td> 0 </Td> </Tr>

What are elements in the first group called