chemistry 2.2

• Types of Bonding


  • Ionic
  • Covalent
  • Metallic
• Intramolecular Forces


  Attraction within a molecule
• Intermolecular Forces

  Attraction between two molecules
• The types of bonding we will be looking at today have to do with the Intramolecular forces. These strong forces are referred to as Primary Bonds
• Ion

  Either positively or negatively charged particles depending on the imbalances between protons (positively charged subatomic particles) and electrons (negatively charged subatomic particles)
• Anion

  An atom with more electrons than protons are negatively charged
• Cation

  An atom with more protons than electrons are positively charged
• Every element on the periodic table wants to be like the noble gasses due to the octet rule (It wants a fully satisfied valence shell or outer shell)

  
• Elements will either lose or gain electrons depending on how close its outer shell is to matching that of a noble gas
• We can use the periodic table to determine how many electrons elements are willing to accept or give up and make predictions about how they will bond

  
• Every element wants to be stable at the lowest energy level and have a full outer shell (valence shell)
• Ions are not stable!
• The net sum of these molecules and compounds that we talk about needs to be zero
• Ionic Bonds


  There is an attractive force that acts between anions (-vely charged ions) and cations (+ively charged ions)
• Ionic Bonds


  Ionic bonds have to do with a transfer of electrons from a metal (usually a cation) to a non-metal (usually an anion), forming a bond
• Ionic Bonds


  These are also known as SALTS
• Ionic Bonds


  • Sodium chloride

  
• Bond Formation


  1. The positive sodium ion and the negative chloride ion are strongly attracted to each other

  2. This attraction, which holds the ions close together, is a type of chemical bond called an ionic bond

  3. The compound sodium chloride, or table salt, is formed

  
• Compound

  A pure substance containing two or more elements that are chemically bonded
• Ionic Compounds

  Produce LATTICE STRUCTURES
• Lattice structures are repeating units of molecules that form massive 3D structures
• Elements can lose or gain more than one electron
• Magnesium

  • Magnesium, Mg, in Group 2 has two electrons in its outer energy level. Magnesium can lose these two electrons and achieve a completed energy level

  
• Some atoms, such as oxygen, need to gain two electrons to achieve stability
• Magnesium Oxide

  • The two electrons released by one magnesium atom could be gained by a single atom of oxygen. When this happens, magnesium oxide (MgO) is formed

  
• Covalent Bonds

  The chemical bond that forms between nonmetal atoms when they share electrons
• Covalent Bonds

  • Water, which is the covalent bonding of hydrogen and oxygen, both non-metals
• Covalent Bonds

  Shared electrons are attracted to the nuclei of both atoms and move back and forth between the outer energy levels of each atom
• Molecule


  The neutral particle formed when atoms share electrons
• Diatomic Molecule


  Two of the same atom have bonded together covalently

  
• Molecular Compound


  A molecule is the basic unit
• Lewis Dot Structure


  A way to represent a covalent bond that helps keep track of valence electrons
• Metallic Bonds

  A force that holds the atoms of metallic substances together
• Metallic Bonds

  • The atoms are closely packed and the electron shells of the metal atoms overlap
  • The valence electrons continuously and freely move between the metal atoms
  • The electrons are non-localized, meaning that they are capable of wandering throughout the entire metal crystalline structure
• Metallic Bonds

  Give metals such as gold and copper the ability to bend and stretch (ductility and malleability)
• Metallic Bonds

  Give metals the ability to conduct electricity, since the electrons are not tied down to a single molecule