Atomic Structure

• Models of the atom have evolved over time, starting as a ball of mass and developing into structures with nuclei and electron shells.
• The atom consists of a nucleus made up of protons and neutrons, surrounded by electrons in electron shells.
• Proton has a relative mass of 1 and a relative charge of +1.
• The atomic number of an atom is determined by the number of protons or electrons it has. (atoms have the same number of p + e)
• The mass number of an atom is the sum of its protons and neutrons.
• Neutron has a relative mass of 1 and a relative charge of 0.
• Electron has a very small relative mass and a relative charge of -1.
• Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
• Electron configuration follows the pattern of the first shell having a maximum of 2 electrons and the rest having a maximum of 8 electrons.
• The number of shells is the period number

  The number of electrons in the outer shell is the group number

  The numbers added together is the atomic number.
• Here are the atomic models

  
• Thompson created the 'Plum Pudding Model'
• Rutherford created the 'Nuclear Model'