Bonding

• What type of elements are sodium and chlorine?

  Sodium is a metal, chlorine is a non-metal
• What do dots and crosses represent in the diagrams?

  Electrons in the outer shells of atoms
• What is the electron configuration of sodium and chlorine?

  Same number of protons and electrons
• Why do many atoms react?

  To achieve noble gas electron configuration
• Which noble gas does sodium resemble after losing an electron?

  Neon
• Which noble gas does chlorine resemble after gaining an electron?

  Argon
• What happens to the sodium atom when it loses an electron?

  It forms a sodium ion with a positive charge
• What charge does the chloride ion have after gaining an electron?

  Negative one
• What do the square brackets in ionic diagrams indicate?

  Charge spread over the whole ion
• What attracts positive and negative ions to each other?

  Electrostatic forces of attraction
• What should you do with the dot and cross diagrams for magnesium and oxygen?

  Complete the diagrams for the ions formed
• How many electrons are transferred from magnesium to oxygen?

  Two electrons
• What noble gas configuration do the ions formed from magnesium and oxygen have?

  Same as the noble gas neon
• What is the process of ionic bonding?

  • Electrons are transferred from metal to non-metal
  • Metal loses electrons, forming a positive ion
  • Non-metal gains electrons, forming a negative ion
  • Resulting ions have noble gas electron configurations
• What are the physical properties of ionic compounds?

  • High melting and boiling points
  • Conduct electricity when dissolved in water
  • Form giant ionic lattices
  • Brittle and hard
• What structure do ionic compounds form?

  A giant ionic lattice
• How do ions in a giant ionic lattice interact?

  They are attracted to oppositely charged ions
• What are the forces that hold ions in a giant ionic lattice together?

  Electrostatic forces of attraction
• What is a key property of ionic compounds regarding melting and boiling points?

  They have very high melting and boiling points
• Why do ionic compounds have high melting and boiling points?

  Strong electrostatic forces require high energy to overcome
• What is the melting point of sodium chloride?

  801 degrees Celsius
• What is the melting point of magnesium oxide?

  2852 degrees Celsius
• Why does magnesium oxide have a higher melting point than sodium chloride?

  Magnesium and oxide ions have higher charges
• In what type of solvents do ionic compounds tend to be soluble?

  Polar solvents like water
• How do water molecules interact with ionic compounds when dissolved?

  They surround the ions and overcome attraction
• What happens to the solubility of ionic compounds with increased ion charges?

  Solubility often decreases
• Why do ionic compounds not conduct electricity when solid?

  Because ions are locked in place
• When can ionic compounds conduct electricity?

  When melted or dissolved in water
• Why can melted or dissolved ionic compounds conduct electricity?

  Because ions are free to move
• What are the properties of ionic compounds explained by the giant ionic lattice?

  • Very high melting and boiling points
  • Soluble in polar solvents
  • Do not conduct electricity when solid
  • Conduct electricity when melted or dissolved
• What is a covalent bond?

  A bond formed by sharing electrons
• What are the steps to draw dot and cross diagrams for covalent molecules?

  1. Identify the atoms involved.
  2. Determine the number of valence electrons.
  3. Show shared pairs of electrons.
  4. Represent the bond with a line.
• What happens during ionic bonding?

  Electrons are transferred from metal to non-metal
• What occurs when a non-metal reacts with another non-metal?

  Covalent bonding takes place
• How many electrons do hydrogen atoms have in their outer shell?

  One electron
• What forms when two hydrogen atoms react?

  The hydrogen molecule H2 is formed
• What is the attraction in a covalent bond?

  The shared pair of electrons is attracted to both nuclei
• What electron configuration do atoms achieve through covalent bonding?

  Same as the nearest noble gas
• How can a covalent bond be represented?

  As a straight line
• How many electrons do fluorine atoms have in their outer shell?

  Seven electrons