* Atomic Number: This defines the element. It's determined by the number of protons in an atom's nucleus. For example, all carbon atoms have 6 protons.
* Mass Number: This represents the total number of protons and neutrons in an atom's nucleus.
* Isotopes: Atoms of the same element (same atomic number) can have different numbers of neutrons. This variation in neutron count leads to different mass numbers, creating isotopes.
Example:
* Carbon-12: Has 6 protons and 6 neutrons (mass number = 12)
* Carbon-14: Has 6 protons and 8 neutrons (mass number = 14)
Both are carbon atoms because they have 6 protons, but they are isotopes due to the different number of neutrons.
Key takeaways:
* Isotopes of the same element have the same chemical properties because they have the same number of electrons.
* Isotopes have different physical properties like mass and density.
* Some isotopes are radioactive, meaning their nuclei decay over time, emitting radiation.
Hope this helps! Let me know if you have any further questions.
