system
Given the following post, respond as if you're commenting on Reddit:
human
Why do materials like some metals with lower heat capacities than water, require so much more heat to liquify?
gpt
They don't actually.

Water melts at 273K, iron at right around 1800K

For one gram of water  go from absolute 0 to fully melted at 273K requires around 600J to heat the ice to its melting point, and then close to another 350 to melt completely for around 950J

For one gram of iron to go from absolute 0 to its melting point of 1800K, it requires around 810, then another 250 to melt to liquid. 1060J to melt the iron.

Now let's talk about why it **seems** to take so much more energy. The most obvious is the fact that 1800+K temperatures are not as common as 273+K temperatures in the universe. And especially here on earth.

Another reason is due to a nice little thing called black body radiation. By the time iron gets to its melting point, it's throwing off so much energy as electromagnetic radiation (light) that it gets harder and harder to pour enough energy into it to overcome this loss. And of course finally there's conductive and convective cooling. Also known as environmental cooling, where it's losing energy to its much lower temperature environment via air, or maybe even worse, water. Overcoming that cooling requires MUCH more energy.