Why Do I Get Shock When I Touch A Metal ?
Remember that ZAP!PP!P ? you must have experienced it at least once probably while sitting on office chair or touching some metal. It’s a quick flow of static current from that object to your body.
So Why Do I Get Shock When I Touch A Metal ?
To understand it, let us begin with understanding the nature of matter. As we all know, everything is made of small atoms and these atoms consist of negatively charged electrons, positively charged protons and neutral neutrons.
In most of the cases, electrons and protons in an atoms balances out makes atom to be neutrally charged. Electrons are tiny and insignificant in mass. Even normal actions like rubbing your hands or legs can provide sufficient energy to these electrons to leave current atom and stick to another and migrating from one object to another.
When this happens, the object that electrons left becomes positively charge since there is no more balance between electrons and protons. Yes you guessed it correctly, likewise objects with more electrons will have negative charge.
Scientifically, this situation is called charge imbalance or net charge separation.
As we always know opposite attracts; when one negatively charged object comes in contact with positively charged object electrons from negatively charged objects start to flow from negative body to positive body. This quick movement of electrons is called static discharge and this is what caused that sudden spark and ZAP!PP!P.
But then why don’t we get static electricity shock all the time ?
Static discharging process doesn’t really happens with any object otherwise you would be getting ZAP!PP!Ped all the time !! Conductors like metals and saltwater tend to have loosely coupled electrons which can easily flow between molecules where as insulators like plastic, glass have tightly coupled electrons those can not even move and then there is third category called as insulators. They allow flow of electrons between molecules not as good as metal but neither as bad as insulators.
To get an static electricity shock first you need to loose electrons which is easily possible with insulators (like floor carpet) because they can get your electrons but won’t give back theirs making you positively charged. Once you are positively charged whatever next negatively charged object to material having conducting properties you touch is going to give you ZAP!PP!P..now you know why do you get shock when you touch a metal.
Watch following animated video to get visual understanding on this phenomenon..
Courtesy : TED-Ed