Mass number, atomic number and isotopes

• Electron number is equal to the number of protons, making an atom not charged.
• Atomic number = protons

  Mass number = proton + neutrons
• Isotopes = atoms of the same element but different number of neutrons
• Isotopes

  • Different isotopes of the same element react the same chemically as they have the same electron configuration
  • They may vary in mass number as they have a different number of neutrons in their nuclei
• All carbon atoms have the same atomic number 6 but may vary in mass number (12, 13, 14)