4.5 Isotopes and Atomic Mass

4.5 Isotopes and Atomic Mass

  • The number of protons, neutrons, and electrons is determined by the atomic number and mass of the atom.

  • Determine the number of protons, neutrons, and electrons in one or more of the isotopes of an element.
  • The atoms of the same element have the same number of protons and electrons.
    • The atoms of most elements have different numbers of neutrons.
  • The element magnesium has an atomic number of 12.
    • Every magnesium atom has 12 protons.
    • Some naturally occurring magnesium atoms have 12 neutrons, others have 13 and still others have 14.
    • The magnesium atoms have different mass numbers but do not change their behavior.
  • There is a left corner.
  • The name and symbol of an isotope can be followed by its mass number.
    • A large sample of naturally occurring magnesium atoms shows that each type of magnesium isotope can be present as a low percentage or a high percentage.
    • The amount of magnesium atoms in the sample is about the same as the amount of Mg-24, but the amount of Mg-25 and Mg-26 is less.
  • The atomic number 24 has 24 protons.
    • The number of neutrons is found by subtracting the number of protons from the mass of each isotope.
  • The formation of bones and teeth requires Vanadium.
    • There are two naturally occurring isotopes of vanadium.
  • The atomic mass is the number that is given below the symbol of each element on the periodic table.
    • The atomic mass on the periodic table is rarely whole numbers because most elements consist of two or more isotopes.
  • The periodic table shows the average mass of a sample of chlorine atoms, but no individual atoms have this mass.
  • There is a higher percentage of 17Cl atoms in the chlorine sample.
  • Atomic mass tABLE is a list of the naturally occurring elements and their atomic mass.
  • We can show how the most abundant isotope is determined for a sample.
  • The atomic mass of magnesium on the periodic table is 24.31.
    • The mass of magnesium is close to the mass of the three isotopes.
  • Magnesium has an atomic mass of 24.31 amu.