<Tr> <Td> oxide type </Td> <Td> refractory dioxide </Td> <Td> refractory dioxide </Td> </Tr> <Tr> <Td> oxide density (g / cm) </Td> <Td> 4.7 </Td> <Td> 4.7 </Td> </Tr> <Tr> <Td> oxide activity </Td> <Td> feebly basic </Td> <Td> feebly basic </Td> </Tr> <Tr> <Td> chloride boiling point (° C) </Td> <Td> under 100 </Td> <Td> 86 (GeCl) </Td> </Tr>

The number of valence electrons of the germanium element is