Question: What component must chocolate have for it to melt at a lower temperature?
About the article "Chocolate", section "Tempering".

Candidate passages:
A eutectic system is a mixture of chemical compounds or elements that have a single chemical composition that solidifies at a lower temperature than any other composition made up of the same ingredients.
This composition is known as the "eutectic composition" and the temperature at which it solidifies is known as the "eutectic temperature".
On a phase diagram the intersection of the eutectic temperature and the eutectic composition gives the "eutectic point".
Non-eutectic mixtures will display solidification of one component of the mixture before the other.
Not all binary alloys have a eutectic point; for example, in the silver-gold system the melt temperature (liquidus) and freeze temperature (solidus) both increase monotonically as the mix changes from pure silver to pure gold. 
The final process is called "tempering".
Uncontrolled crystallization of cocoa butter typically results in crystals of varying size, some or all large enough to be clearly seen with the naked eye.
This causes the surface of the chocolate to appear mottled and matte, and causes the chocolate to crumble rather than snap when broken.
The uniform sheen and crisp bite of properly processed chocolate are the result of consistently small cocoa butter crystals produced by the tempering process.
The fats in cocoa butter can crystallize in six different forms (polymorphous crystallization).
The primary purpose of tempering is to assure that only the best form is present.
The six different crystal forms have different properties.
As a solid piece of chocolate, the cocoa butter fat particles are in a crystalline rigid structure that gives the chocolate its solid appearance.
Once heated, the crystals of the polymorphic cocoa butter will be able to break apart from the rigid structure and allow the chocolate to obtain a more fluid consistency as the temperature increases.
This is known as the melting process.
When the heat is removed, the cocoa butter crystals will become rigid again and come closer together, allowing the chocolate to solidify.
This temperature in which the crystals obtain enough energy to break apart from their rigid conformation would depend on the milk fat content in the chocolate and the shape of the fat molecules as well as the form of the cocoa butter fat.
Chocolate with a higher fat content will melt at a lower temperature.
Making chocolate considered "good" is about forming as many type V crystals as possible.
This provides the best appearance and texture and creates the most stable crystals, so the texture and appearance will not degrade over time.
To accomplish this, the temperature is carefully manipulated during the crystallization.
Generally, the chocolate is first heated to to melt all six forms of crystals.
Next, the chocolate is cooled to about , which will allow crystal types IV and V to form.
At this temperature, the chocolate is agitated to create many small crystal "seeds" which will serve as nuclei to create small crystals in the chocolate.
The chocolate is then heated to about to eliminate any type IV crystals, leaving just type V. After this point, any excessive heating of the chocolate will destroy the temper and this process will have to be repeated.
However, there are other methods of chocolate tempering used.
The most common variant is introducing already tempered, solid "seed" chocolate.
The temper of chocolate can be measured with a chocolate temper meter to ensure accuracy and consistency.
A sample cup is filled with the chocolate and placed in the unit which then displays or prints the results.
Two classic ways of manually tempering chocolate are:
 Working the molten chocolate on a heat-absorbing surface, such as a stone slab, until thickening indicates the presence of sufficient crystal "seeds"; the chocolate is then gently warmed to working temperature.
 Stirring solid chocolate into molten chocolate to "inoculate" the liquid chocolate with crystals (this method uses the already formed crystals of the solid chocolate to "seed" the molten chocolate).
Chocolate tempering machines (or temperers) with computer controls can be used for producing consistently tempered chocolate, particularly for large volume applications.
Chocolate chips can be used in cookies, pancakes, waffles, cakes, pudding, muffins, crêpes, pies, hot chocolate, and various types of pastry.
They are also found in many other retail food products such as granola bars, ice cream, and trail mix.
Chocolate chips can also be melted and used in sauces and other recipes.
The chips melt best at temperatures between 104 and 113 °F (40 and 45 °C).
The melting process starts at around 90 °F when the cocoa butter in the chips starts to heat.
The cooking temperature must never exceed 115 °F (for milk and white) or 120 °F (for dark) or the chocolate will burn.
Although convenient, melted chocolate chips are not always recommended as a substitute for melted baking chocolate.
Because most chocolate chips are designed to retain their shape when baking, they contain less cocoa butter than baking chocolate.
This can make them more difficult to work with in melted form. 
Glue guns come in low-temperature and high-temperature (hot-melt) versions.
Low-temperature glue guns operate at approximately and are well suited when high temperatures are undesirable, such as gluing lace and cloth.
High-temperature guns operate at approximately and produce a stronger bond.
"Dual guns" have a switch for both low- and high-temperature use.
In addition to bonding surfaces together, hot-melt glue can be used to fill gaps, but the properties that allow gap-filling (high viscosity, high toughness, and so on) keep it from forming an adhesive film as thin and smooth as is possible with other adhesives.
(For example, a wood joint properly made with hide glue may be invisible, marked only by a difference in grain at the seam line.)
Bonds must be made quickly before the glue has time to harden.
Usually it must be applied accurately with the glue gun, as it can not easily be spread, but it is always possible at any time to melt and spread the glue with a heat gun or a household clothes iron, which helps when bonding larger areas.
Surprisingly, hot-melt glue can be used to assemble and repair foam models as an alternative to foam-safe Cyanoacrylate or UHU POR adhesive.
Due to the insulating properties of the foam the hot-melt glue remains sticky for much longer than when used on wood, metal or plastics.
Another development of glue gun technology allows the user to 'spray' an area with a semi-pressure sensitive hot melt adhesive.
Using compressed air to force the adhesive at a controlled rate through a specially developed glue gun nozzle, a spiral pattern of adhesive is applied.
The tackiness of the adhesive / open time is limited to just a few minutes, after which the adhesive will lose its tack, so coverage is limited. 
The potato chips used are usually the regular or plain tasting ridged shaped potato chips.
Ridged chips are used because they tend to be more sturdy and can hold the heavy chocolate.
It also allows the chocolate flavor to be enhanced as the chocolate is allowed to build between the ridges of the chip.
The kind of chocolate used is usually milk chocolate that is easily tempered for coating other foods.
The tempering of chocolate is to basically melt chunks of chocolate into a liquid form in order to create a coating for whatever the chocolate will be used to cover or coat.
Chocolate covered potato chips may also be found in the gourmet section of grocery stores or at a specialty foods store.