Atomic structure and periodic table

• The mass of an atom is contained in the nucleus where the protons and neutrons are located
• The atom is the smallest part of an element that exists
• An element is a substance made from one type of atom
• atomic number

  Number of protons in atom
• Atomic mass

  Number of protons and neutrons in an atom
• The atomic mass tells us which element it is
• Protons have a relative mass of 1
• Protons have a charge of +1
• Neutrons have a relative mass of 1
• Neutrons have a charge of 0 ( neutral )
• Electrons have a relative mass of 0
• Electrons have a charge of -1
• elements are arranged in order of increasing atomic number
• All elements in the same group have the same number of electrons in their outer shell
• As you go down each period ( row), the number of electron shells increases
• electrons orbit around the nucleus
• • The ending ‘-ite’ will always have less oxygen than ‘-ate’