Atomic structure

-the chemical elements are different from the other  by the # of proton
 E.g- N:7 proton in the nucleus
    - O:8 proton in the nucleus
    - Cl: 17 proton in the nucleus

-Atomic Number: the number of protons in the nucleus
 
    ---A neutral atom has no charge, # of electrons = # of protons
E.g: The atomic number of Cl is 17
     -any atom of Cl has 17 protons
     -a neutral Cl has 17 electrons
-electrons are gained or lost roam neutral atom is called Ion
---------------------------------------------
Atomic Mass is the total number of protons ans neutrons
 ∴ #of protons + #of neutrons = Atomic Mass
    E.g Carbon 12/6 C
        #of protons = atomic number = 6
        #of electrons = 6
        #of neutrons = 12-6=6
------------------------------------------------
Isotopes are atomic species having the same atomic number but different atomic masses
E.g  19/9 F + 1/0n ----20/9 F
-----------------------------------------