<Dd> Ba + 2 ROH → Ba (OR) + H ↑ (R is an alkyl group or a hydrogen atom) </Dd> <P> Barium reacts with ammonia to form complexes such as Ba (NH). </P> <P> The metal is readily attacked by most acids . Sulfuric acid is a notable exception because passivation stops the reaction by forming the insoluble barium sulfate on the surface . Barium combines with several metals, including aluminium, zinc, lead, and tin, forming intermetallic phases and alloys . </P> <Table> Selected alkaline earth and zinc salts densities, g / cm <Tr> <Th> </Th> <Th> O </Th> <Th> </Th> <Th> </Th> <Th> Cl </Th> <Th> SO </Th> <Th> CO </Th> <Th> O </Th> <Th> </Th> </Tr> <Tr> <Th> Ca </Th> <Td> 3.34 </Td> <Td> 2.59 </Td> <Td> 3.18 </Td> <Td> 2.15 </Td> <Td> 2.96 </Td> <Td> 2.83 </Td> <Td> 2.9 </Td> <Td> 1.7 </Td> </Tr> <Tr> <Th> Sr </Th> <Td> 5.1 </Td> <Td> 3.7 </Td> <Td> 4.24 </Td> <Td> 3.05 </Td> <Td> 3.96 </Td> <Td> 3.5 </Td> <Td> 4.78 </Td> <Td> 3.26 </Td> </Tr> <Tr> <Th> Ba </Th> <Td> 5.72 </Td> <Td> 4.3 </Td> <Td> 4.89 </Td> <Td> 3.89 </Td> <Td> 4.49 </Td> <Td> 4.29 </Td> <Td> 4.96 </Td> <Td> 4.16 </Td> </Tr> <Tr> <Th> Zn </Th> <Td> 5.6 </Td> <Td> 4.09 </Td> <Td> 4.95 </Td> <Td> 2.09 </Td> <Td> 3.54 </Td> <Td> 4.4 </Td> <Td> 1.57 </Td> <Td>--</Td> </Tr> </Table>

What is the elements name and symbol that comes after barium