BASICS OF ELECTRICITY :part-1

• Topic:fundamentals of elecctricity
• Matter is composed of very tiny             particles called atoms.                       
•   An atom is made of three                  fundamental particles namely                *electrons *protons and *neutron    
• In the normal state,the number of electrons is equal to the number of protons an atom,therefore an atom    is neutral at whole.but if we talk about the location of neutrons and protons they lie in the nucleus but the electrons lie on the orbit of an atom.
• *Atomic number of an element:This is equal to the total positive charge(protons) present in an atom.
• *mass number of an atom:this is equal to the sum of protons+total number of neutrons
• Note:protons and neutrons             togetherly known as nucleons.  
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• cations:when there is an excess of electrons in atom ,then it forms +ve charge ion and called cation.but if there is the deficit  )of electrons ,then it forms -vely charged ions called anions.

Charge:It is the property of fundamental particles atoms due to which they attract or repel each other. Charge is of two types :1) positive charge, 2) Negative charge  
some necessary points about charge:1) It is a scale quantity. 2)In S. I system unit of charge is coulomb. 3)Benzamin Franklin introduced the concept of charge 4)note.: like charges repel each other and  unlike charges attract each other .
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• Some properties of charges:1) charge is conserved  I. e it can neither be created nor be destroyed. It can only transferred from ooobject to another. 
• 2) Charge is quantised. It means the the smallest charge is associated with electron and protons. It broadly in sense 

      *All charges in nature exist as integral multiples of electron charge that is q = n X e                   Where n is an integer.

• Charge contained by one electron=1.6x 10^(-19) coulmb. 
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• Note. :1> when a body is positively charged, its mass slightly decrease but when a body is negatively charged its mass slightly increases. 
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• In  case of a conductor charge spread over the entire outer surface and in case of insulator, its charge is localised 
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• 1. Define the term electrification: The process of making a neutral body into a charged body is known as electrification.
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• 2. electrification is a Universal phenomenon.
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• 3.A body can be charged by any of the following three ways aA)friction B) contact C electrostatic induction
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• Charging by friction: when we rub to neutral bodies, there will be some transfer of electrons from one body to other due to structural modifications because of the frictional forces acting on them. 
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• In this method one of the bodies acquire a negative charge while the other gets a po
• sitive charge, both of which are equal in magnitude.
• example