Properties of simple molecular substances

• What type of bonds do simple molecular substances have?

  Covalent bonds
• What is formed when two hydrogen atoms share their electrons?

  Hydrogen molecule
• What process defines covalent bonding?

  Sharing of electrons
• Match the molecule with the number of electron pairs shared:

  N2 ↔️ 3 pairs

  O2 ↔️ 2 pairs

  H2O ↔️ 1 pair with each H

  CO2 ↔️ 2 pairs with each O
• How many electrons does oxygen share in the molecule H2O?


  2
• Simple molecular substances are larger than giant molecular structures.

  False
• Simple molecular substances have strong intermolecular forces.

  False
• What are the relative abundances of the major gases in air?

  • Nitrogen (N2): 78%
  • Oxygen (O2): 21%
  • Carbon dioxide (CO2): 0.04%
  • Water vapor (H2O): Variable
• What is the chemical formula for water?

  H2O
• Match the property with its description for simple molecular substances:

  Structure ↔️ Small molecules

  Bonding ↔️ Covalent bonds

  Melting Point ↔️ Low

  Conductivity ↔️ Poor
• Match the key concept with its description:

  Sharing of electrons ↔️ Atoms share electrons to fill their outer shells

  Formation of molecules ↔️ Shared electrons hold atoms together
• What is the typical melting point of simple molecular substances?

  Low
• What is the chemical formula for oxygen?

  O2
• What happens when a simple molecular solid is heated to its melting point?

  Intermolecular forces break
• How can the information in the image be used to understand the composition of air?

  • The image provides a clear visual representation of the relative abundances of the major gases in air.
  • This information can be used to understand the overall composition of air and the proportions of the different gases present.
  • The data can also be used to compare the abundances of the gases and identify the most and least abundant components of air.
• What type of bond is formed when atoms share electron pairs?

  Covalent bond
• Atoms share electrons in covalent bonding to achieve a full outer electron shell.

  True
• Simple molecular substances require a large amount of energy to melt due to their strong intermolecular forces.

  False
• What is the chemical formula for nitrogen?

  N2
• Why do simple molecular substances not conduct electricity?

  They lack free electrons
• Match the term with its description:

  Intermolecular forces ↔️ Weak forces holding molecules together

  Van der Waals forces ↔️ Type of intermolecular force

  Melting point ↔️ Temperature at which a substance melts
• Match the property with the substance type:

  Conduct electricity ↔️ Metals: Good || Simple Molecular Substances: Poor

  Free electrons ↔️ Metals: Many || Simple Molecular Substances: None
• Why do simple molecular substances have low melting points?

  Weak intermolecular forces
• Carbon shares 4 electrons with each oxygen in the molecule CO2.

  True
• Simple molecular substances can have ions present.

  False
• What is the chemical formula for carbon dioxide?

  CO2
• What is the term for the particles that transport electricity in a substance?

  Charge carriers
• What are the key differences between the major gases in air?

  • Nitrogen (N2) is an inert gas, while oxygen (O2) is essential for respiration.
  • Carbon dioxide (CO2) is a greenhouse gas, while water vapor (H2O) is a variable component.
  • The abundances of the gases vary significantly, with nitrogen being the most abundant and carbon dioxide being the least abundant.
• How can the abundance of gases in air be represented visually?

  • The relative abundances can be shown using a bar chart or graph, with the bars or segments proportional to the percentages of each gas.
  • The image uses a triangular shape to visually represent the relative abundances, with the largest segment for nitrogen, followed by oxygen, and the smallest segment for carbon dioxide.