periodic table

• Atom


  The smallest particle of an element that can take part in a chemical reaction
• Element


  Substances that cannot be broken down into anything simpler
• Development of the periodic table

  Discovered by Dmitri Mendeléev in 1869
• Proton


  A positively charged particle located at the center of the atom in the nucleus

  
• Electron


  A negatively charged particle that spins around the outside of the nucleus

  
• Neutron


  A particle without any charge that affects the mass and radioactivity of the atom
• The hydrogen atom is unique in that it only has a single proton and no neutron in its nucleus
• Electrons are much smaller than neutrons and protons, about 1800 times smaller
• The most abundant element in the earth's crust is oxygen
• Periodic table


  Contains all the known chemical elements arranged according to structure

  
• Periodic table


  • A row across is called a period
  • A column is called a group
  • Helps obtain basic information about each of the 118 known elements

  
• Atomic number


  Refers to how many protons an atom of that element has
• Atomic mass


  The "weight" of the atom, derived by adding the number of protons with the number of neutrons
• Element symbol


  A unique symbol consisting of a single capital letter, or a capital letter and one or two lower case letters
• Common element symbols

  • C (Carbon)
  • Cu (Copper)