2.5 Covalent Bonding

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

  The formation of covalent bonds by sharing electrons
• How do atoms form ionic bonds?

  By transferring electrons from one atom to another
• What happens to atoms when they transfer electrons to form ionic bonds?

  They become oppositely charged ions that attract each other
• Why do atoms transfer electrons?

  To achieve a full outer shell of electrons
• What occurs when two non-metal elements, like chlorine atoms, interact?

  They share electrons instead of transferring them
• What is a dot and cross diagram used for?

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

  By using dots for one atom and crosses for the other
• What is a displayed formula?

  A representation using chemical symbols and lines to show covalent bonds
• Why are displayed formulas advantageous for drawing large molecules?

  They simplify the representation of complex structures
• What is a limitation of displayed formulas?

  They do not show the 3D shape of the molecule
• What is the molecular formula for ammonia?

  NH₃
• How many hydrogen atoms are in an ammonia molecule?

  Three hydrogen atoms
• How does hydrogen's first energy level affect its electron sharing?

  It can hold a maximum of two electrons
• How many extra electrons does nitrogen need to fill its outer shell?

  Three extra electrons
• What do we do to create a displayed formula from a dot and cross diagram?

  We remove the shells and place lines for covalent bonds
• What is the result of each hydrogen atom sharing one electron with nitrogen in ammonia?

  All atoms achieve full outer shells
• What is a 3D model used for in chemistry?

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

  Small molecules joined by strong covalent bonds
• What are two examples of simple molecular substances?

  Water (H₂O) and methane (CH₄)
• What are polymers made of?

  Long chains of repeating units called monomers
• What are giant covalent structures?

  Large structures involving billions of atoms in a regular lattice
• What are some examples of giant covalent structures?

  Silicon dioxide, diamond, and graphite
• Why are giant covalent structures strong?

  All atoms are joined by covalent bonds
• What is the main takeaway from the video?

  Understanding covalent bonds and their representations