◄Back

# Long description

This is a diagram illustrating the different phases that water can take. It is an x-y graph, with temperature (in degrees Celsius) on the horizontal (x) axis and pressure (in mega pascals) on the vertical (y) axis. The x and y axes cross at approximately -75 degrees Celsius 0 mega pascals. The x axis reads from -75 to 150 degrees Celsius and 0 °C and 100 degrees Celsius are labelled. The y axis has a logarithmic scale and reads from 0 to 1 mega pascal, but only 0.1 mega pascals is labelled, about half way up the axis. The diagram is divided into three areas by three lines. Central to this is a point at about one quarter above the x-axis at 0.06 mega pascals and about one third to the right of the Y-axis at 0 °C. This is labelled the triple point of water. From the origin of the graph to the triple point a concavely curved line divides two areas – one to the right of the line labelled gas (steam) and one above the line labelled solid (ice). The line ends at the triple point. From there, another line extends, also concavely curved through a point marked at 0.1 mega pascal and 100 °C up towards the top of the diagram. This line divides the area labelled gas (steam) from an area labelled liquid (water). A third line extends from the triple point to the top of the diagram, running slightly back towards the y axis. This line divides the areas labelled solid (ice) on the left of the line from the area labelled liquid (water) to the right of the line.