Isotopes

• These are atoms of the same elements, with the same number of protons but different number of neutrons.
• Isotopes have same atomic number but different mass number
• Not ALL elements can exist as isotopes
• neutrons= mass number no. - atomic no.
• Isotopes have different physical properties e.g. density, boiling points etc. Due to the difference in the Mass no.
• They also have same chemical properties e.g. clue to the presence of the same numbers of electrons (in the outermost shells)
• Atoms react by gaining/losing electrons in the outermost shell to become stable. Hence similar chemical properties