L5 LDS COVALENT COMPOUND

• Atomic size

  • The property determined by the atomic radius of an element.
  • It increases from top to bottom in a group.
  • Atomic size decreases from left to right in a period.
• • Ionization energy is the minimum amount of energy required to remove an electron from a gaseous atom in its ground state. 
  • It increases from left to right across a period. 
  • Elements with small ionization energy tend to easily give up electrons to become positive ions or cations.

  
• • Electron affinity of an atom is the energy change that occurs when a gaseous atom accepts an electron.
  • It increases from left to right across a period.
  • The greater the electron affinity, the greater the tendency for an atom to accept an electron and form a negative ion or anion.

  
• • Electronegativity is the ability of an atom to attract toward itself the electrons in a chemical bond. 
  • This property of an atom tells if an atom can form a covalent molecule or compound with another atom.

  
• Metallic Property

  • This is a measure of the tendency of an atom to lose electrons.
  • Large atoms are metallic small; small atoms are less metallic.
  • The most metallic elements are the largest atoms found on the upper right side of the table.

  
• Valence periodicity

  • This property is exhibited most consistently among the representative elements in Group 1A, which have one valence electrons; Group IIA two valence electrons, and Group IIIA, which have three valence electrons. 

  
• STUDY AND ANALYZE

  
• Atomic size

  • INCREASES FROM TOP TO BOTTOM (GROUP)
  • ATOMIC SIZE DECREASES FROM LEFT TO RIGHT (PERIOD)
• Atomic size

  • INCREASES FROM TOP TO BOTTOM (GROUP)
  • ATOMIC SIZE DECREASES FROM LEFT TO RIGHT (PERIOD)
• Ionization energy

  • INCREASES FROM LEFT TO RIGHT (PERIOD)
• Ionization energy

  • INCREASES FROM LEFT TO RIGHT (PERIOD)
• Electron affinity

  • INCREASES FROM LEFT TO RIGHT (PERIOD)
  • THE GREATER THE ELECTRON AFFINITY, THE GREATER THE TENDENCY FOR AN ATOM TO ACCEPT AN ELECTRON AND FORM A ANION.
• Electronegativity

  • starting from Fr and ending on F, having the highest electronegativity
• Metallic Property

  • most metallic elements are the largest atoms found on the upper right side of the table
• Covalent Compounds

  • a type of bond in which two electrons are shared by two atoms. For simplicity, the shared pair of electrons is often represented by a single line -. 

  
• • Are made up of non-metals or a non-metal and metalloid.
  • Formed by covalent bonding. 
  • Occurs through a process called electron sharing.
  • There can be multiple covalent bonds between two atoms
• Types of covalent bonds

  • a single bond is formed when two atoms share a pair of electrons, double bond when two pairs of electrons are shared, and triple bond when three pairs of electrons are shared. 

  
• How to Draw 

  Lewis Dot Structures

  Step 1: Count all the Valence Electrons

  1. CO2 (carbon dioxide)

  • 4 + 6 (2) = 16

  1. N2O (dinitrogen monoxide)

  • 5 (2) + 6 = 16 

  1. CH4 (methane)

  • 4 + 1 (4) = 8
• Step 2: Put the least electronegative element in the center. (H always goes on the outside)

  1. CCl4 (carbon tetrachloride)

  • C = central atom

  1. CH4 (methane)

  • C = central atom
• • NOTE:
  • As we go towards the Fluorine, we become more electronegative.
  • Elements closer to Fluorine are more electronegative.
• 1. SF4 (sulfur tetrafluoride)

  • S = central atom

  1. H2O (water)

  • O = central atom
• Step 3: Put a pair of electrons between atoms to form the chemical bond

  
• study and analyze