There are two materials A and B out of which one is a metal and second is a semiconductor . How can we identify and classify them just by touching or observing them without performing any test?
I don't know if it is applicable under the restrictions above but generally the Hall effect measurement is straightforward indicator (Hall carrier mobility measurement). It can be done by 4 -contacts probe, just needs strong magnetic field.
Otherwise, one can observe infrared/ visible light properties related to bandgap.
Also, in many case one can use this technique https://www.jove.com/pdf/59007/jove-protocol-59007-carrier-lifetime-measurements-semiconductors-through-microwave
I remember physical practics where we solved the similar problem. The answer was to measure electrical resistance during heating of the material. You should get increase of resistivity for metal and decrease for semiconductor. Try it. You need just multimeter and some source of heat.
dear colleague
i dont think whether it is possible to do it without any test or measurements
regards
try breaking it. simple metals are generally more ductile. but there is no guaranteed test without equipment.
Dear Amit Das ,
I second Andrey Porokhnyuk . One of the main difference between the metal and semiconductor sis that the metal is ductile and they will not break when you hammer them while the semicondcutor will be splattered into small parts. The semiconductors are fragile and brittle while the metal are ductile ands nonbrittle.
The other property that can be sued is the metals are highly light reflective while the semicondcutor is partially reflective.
Best wishes
Dear Amit Das ,
This is an interesting question with much limitations. :)
(No test??? Touching and observing are also some sort of tests)
On the other hand, I am not sure whether a general answer can be given which can be valid for any arbitrary types of semiconductor/metal couple's comparison.
I have some ideas, anyway, but -I regret- with some (yet plain/practical) tests.
Assuming the parts have comparable size/geometry, I would apply one of the following:
i) I would heat both up with the same heating source, then let them cool down a couple of seconds and touch them at the same instant to feel which one cooled down faster (That one would be metal, since metals usually have relatively larger thermal conductivity than semiconductors).
ii) I would put both into a microwave oven (which may not be good for the microwave oven :) ) and wait to see which one gives out glittering sparks (maybe a wrong term - whatever :) ).
P.S.: To be honest, I am not very good at chemistry, so if there are any fundamental mistakes in my estimations, your correcting/improving comments are welcome.
Best regards...
If this question was posed in a Ph.D. dissertation, it was probably asking about the difference between optical properties of metals and semiconductors. Therefore, the proper answer is to differentiate between their absorption and reflectivity of light.
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