Melting Points for Dummies

Heat, latent heat, and melting point

It doesn't take long before any new member of the Antisocial Network research staff figures out that a lot of the misinformation floating around the internet was put there by people who were more interested in money than accuracy. Take, for instance, the entire family of Demand Media websites: take them, please! Much of the rubbish presented by eHow.com contributors arises from their lack of familiarity with their topic, particularly liberal arts grads faced with science topics: liberal arts grads like PolySci type Tom Lutzenberger, attempting to explain the scientific basis of "What Forces Must Be Overcome for a Substance to Melt?"¹ Tom's skills at misinformation have already earned him six DotD awards...

It isn't so much that Lutzenberger's "facts" are wrong, exactly; it's that his explanation is so clumsy that it's silly. It's obviously reworded from a more authoritative source, but the clumsy rewording and massive padding needed to meet the DMS² minimum word count are... well, let Tom's words speak for themselves:

"The physical property of a substance tends to be defined by its melting point as it relates to nature." Is that another way to say that melting point is one physical property of a substance? "...if its normal state is as a solid, the environment needs to be changed to make it liquid..." Umm, yeah: that's what "melting" means! "The most common obstacle to achieving a melting point involves raising the surrounding temperature to a hot enough level to change the molecular makeup of the material." Wordy much, Mr. Lutzenberger? "For a solid to properly melt, the change in environment needs to be contained. Otherwise, the energy involved escapes to the surrounding space and air." Wait: does that mean that you can't melt an ice cube unless you put it in a little box? And how does something melt "improperly"? "Some materials will have a higher resistance to melting than others. Clearly steel and wood take more heat to burn than an ice cube." FYI Tom, burning isn't the same thing as melting! "The more dense the material, such as steel, the hotter it will need to be to melt." No, Tom, density is not a predictor of melting point.

Obviously, Tom spent a lot of time on this. It's sad, however, that Tom only briefly approached the actual answer to that question. He did so when he said,

"The most common obstacle to achieving a melting point involves raising the surrounding temperature to a hot enough level to change the molecular makeup of the material. At the atomic level the molecules need to be sped up enough to lose their normal structured integrity that make the substance a solid."

In fact, that's sort of correct (although TL clearly thinks "atomic level" and "molecules" are the same thing): a more authoritative answer (one written by someone who knows the answer) is "In order for a substance to melt, it must absorb enough energy to overcome the intermolecular bonds holding its molecules together." Lutzenberger probably didn't understand that – note no reference to the "latent heat of fusion" – which means he's won yet another Dumbass of the Day award for his troubles.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was    ehow.com/info_8415034_forces-must-overcome-substance-melt.html
² DMS is Demand Media Studios (now known as Leaf Group). Around here, we like to say, "You can't spell 'dumbass' without 'DMS'!"

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