atoms and molecules ang periodic table

• Atom


  The smallest particle of a substance that can exist on its own
• Atom


  A form of matter which may not be further broken down using any chemical means
• Atom


  In Greek, "atomos" means uncuttable
• Structure of an Atom

  An atom contains Protons, Neutrons, Electrons. The centre is called the nucleus. The nucleus contains protons and neutrons. Electrons orbit the nucleus. Most of the atom is empty space
• Currently scientists know of 118 different elements
• Element


  A pure substance made entirely from one type of atom
• Element


  Everything is made up of atoms of different types of elements
• Element


  Each element has a unique set of physical and chemical properties
• Each element has a unique


  • Symbol, Atomic number
• Periodic Table


  Scientists sorted all the elements based on their chemical and physical properties. They arranged them in a table by grouping similar features together
• Dmitri Mendeleev formulated the Periodic Law and created a version of the periodic table of elements
• Mendeleev left blank spaces for undiscovered elements, which turned out to be correct
• Mendeleev broke the pattern of increasing atomic weight to keep similar reacting elements together
• Elements in the same group on the periodic table have similar chemical and physical properties
• Columns on the periodic table are grouped into families with names
• Aluminium was once rare but is now discarded as soda cans without a care
• Carbon is to humans what Silicon is to computers
• Molecule


  Formed when two or more atoms join together chemically
• Compound


  A type of molecule that contains at least two different elements