ATOMIC NUMBER (Z) AND MASS NUMBER (A) – ISOTOPES
ATOMIC NUMBER (Z): The amount of protons in the nucleus gives the element its identity and properties, that’s why it is called atomic number
ATOMIC MASS(A): (ALSO CALLED NUCLEON NUMBER) It’s the total amount of particles in the nucleus. (Protons + Neutrons)
ISOTOPES: Atoms MUST HAVE the same number of protons if they belong to the same element, but they can also have DIFFERENT amount of neutrons. these different variations of the same element are called isotopes
Atoms with more or less electrons in the electron cloud are called IONS. We have to show the charge when we represent the ion indicating if it is negative, positive and how many charges it has.
HOW DO WE REPRESENT ATOMS?
The picture shows: X as the element, the zone where we need to indicate the mass and atomic number, so as to the charge of the ion (if any).
