If the melting temperature of hydrogen is -259°C and the melting temperature of oxygen is -218°C then why is the melting temperature of water (H2O) 0°C?

Question

Shouldn’t it be around -245°C?

In: Chemistry

Answer 1

You can’t just average the melting point like that. There are many different things that influence melting point, such as the composition of whatever you’re melting (the closer you pack atoms together, the higher the melting point will be), and how the atoms are bonded together. That’s why even a relatively small change can change the melting point drastically.