2.1.1/2- Atomic Structure,Isotope,Compound,Formulae,Equation

• Atomic Number


  The number of protons in the nucleus of an atom
• Bohr Model


  • Describes an atom as a small dense nucleus with electrons orbiting around the nucleus
  • Explains different periodic properties of atoms
• Electron


  • A negatively charged subatomic particle which orbits the nucleus at various energy levels
  • The relative mass of an electron is 1/1836
• Ion


  A charged atom or molecule
• Isotopes


  • Atoms of the same element with the same number of protons and electrons but different numbers of neutrons
  • Isotopes of an element have different masses
• Mass Number


  The total number of protons and neutrons in the nucleus of an atom
• Mass Spectrometry


  An instrument which gives accurate information about relative isotopic mass and the relative abundance of isotopes
• Neutron


  • A neutral subatomic particle found in the nucleus of an atom
  • The relative mass of a neutron is 1
• Proton


  • A positively charged subatomic particle found in the nucleus of an atom
  • The relative mass of a proton is 1
• Relative Abundance


  The amount of one substance compared with another
• Relative Atomic Mass


  The weighted mean mass of an atom compared with 1/12th mass of an atom of carbon-12
• Relative Isotopic Mass

  The mass of an atom of an isotope compared with 1/12th mass of an atom of carbon-12
• Relative Formula Mass

  • The mass of the formula unit of a compound with a giant structure
  • For example, NaCl has a relative formula mass of 58.44 g mol
• Relative Molecular Mass (M,)


  The mass of a simple molecule
• Ammonium ion


  An ion with the formula NH,*
• Carbonate


  An ion with the formula CO"
• Hydroxide


  An ion with the formula OH
• Ionic Compound


  A compound which is made up of oppositely charged ions that are held together by electrostatic forces
• Nitrate


  An ion with the formula NOz:
• Silver ion


  Has the formula Ag*
• State symbols


  • Symbols within a chemical equation which indicate the state of each compound under the reaction conditions
  • (g) gaseous, (1) liquid, (s) solid and (aq) aqueous
• Sulfate


  An ion with the formula SO,
• Zinc ion


  Has the formula Zn+