Michaelmas Chemistry Year 9

• Proton


  A positively charged particle found in the nucleus of an atom.
• Neutron


  A particle with no charge found in the nucleus of an atom, affecting its mass number.
• Electron


  A negatively charged particle found in energy levels around the nucleus of an atom.
• Atomic Number 


  The number of protons in an atom's nucleus, determining the element.
• Mass Number

  The total number of protons and neutrons in an atom's nucleus.
• Isotope


  Atoms of the same element with the same number of protons (atomic number) but differing numbers of neutrons.
• Mendeleev's Periodic Table


  A table organizing elements by atomic mass and chemical properties.
• Mendeleev's Concept


  Arrange elements by atomic mass and chemical properties to show relationships
• Rows (Periods)


  Elements are arranged by atomic number (number of protons) in rows.
• Columns (Groups)


  Elements are arranged by chemical properties in columns.
• What is an ion?


  Any atom or group of atoms that has one or more positive or negative electrical charges.