1.which are the fundamental particles whose masses are mainly responsible for the mass of an atom? give reasons ? 2.what is the mass of a Proton ?

3.what about the mass of a Neutron ?

4.what will be the mass of an atom having only one proton and one neutron ?

5.find the mass of an atom having two protons and two neutrons?

6.is there any relation between the total number of protons and neutrons in an atom and its mass ?

7.which is the fundamental particles of an atom that can be displaced when atoms rub against each other or they undergo chemical reaction with other atoms? give reasons ?​

Amath expression is a collection of one or more terms, which are separated by the signs ( + , - , x , / ).example :   8+b8+b  or  a−3a−3in algebra, an equation is a mathematical statement with two expressions where, each expression is separated by an equal (=) sign. variables can be present on both the sides of the equality (=) sign and we use letters to denote such variables.example 1:   x=4+2x=4+2  , [here, we can observe that the variable is present only on one side of the equation].example 2:   2x+3=x+42x+3=x+4  , [here, we can observe that the variables are present on both side of the equation].