Covalent Bonding

• What is the main topic of today's video?

  Covalent bonds and their representations
• How do atoms form covalent bonds?

  By sharing electrons
• What happens when atoms transfer electrons?

  They form oppositely charged ions
• Why do atoms transfer electrons?

  To achieve a full outer shell
• What do two chlorine atoms need to achieve a full outer shell?

  They need to share electrons
• What is a dot and cross diagram used for?

  To represent shared electrons in covalent bonds
• How should you differentiate the atoms in a dot and cross diagram?

  Use dots for one atom and crosses for another
• What is a displayed formula?

  A representation using chemical symbols and lines
• What is the advantage of using a displayed formula?

  It simplifies drawing large molecules
• What is a limitation of displayed formulas?

  They do not show 3D molecular shapes
• What is the molecular formula for ammonia?

  NH₃
• How many hydrogen atoms are in ammonia?

  Three hydrogen atoms
• How does nitrogen achieve a full outer shell in ammonia?

  By sharing electrons with three hydrogens
• What is the maximum number of electrons hydrogen can hold?

  Two electrons
• What is the maximum number of electrons nitrogen can hold?

  Eight electrons
• What do you do to create a displayed formula from a dot and cross diagram?

  Replace shared electrons with lines
• What is a 3D model used for in chemistry?

  To show the arrangement of atoms
• What are simple molecular substances?

  Small molecules with strong covalent bonds
• What are polymers made of?

  Repeating units called monomers
• What are giant covalent structures?

  Large structures with billions of atoms
• Why are giant covalent structures strong?

  All atoms are joined by covalent bonds
• What is the main focus of the video?

  Covalent bonds and their types