Further , a trend for hydrogen halides , or HX , is that enthalpy of formation becomes less negative , i.e. , decreases in magnitude but increases in absolute terms , as the halide becomes larger .
This results in elemental hydrogen gas and astatine precipitate .
A trend for hydrogen halides , or HX , is that enthalpy of formation becomes less negative , i.e. , decreases in magnitude but increases in absolute terms , as the halide becomes larger .
This results in elemental hydrogen gas and astatine precipitate .