Question 1: Define a simple molecule and provide two examples commonly found in nature.

Answer: A simple molecule is a molecule made up of a small number of atoms held together by covalent bonds, such as water (H₂O) and carbon dioxide (CO₂).

Question 2: Explain how covalent bonds are formed between atoms in simple molecules.

Answer: Covalent bonds are formed when two atoms share one or more pairs of electrons, allowing each atom to achieve a stable electron configuration.

Question 3: Calculate the molar mass of a water molecule (H₂O). Use atomic masses: Hydrogen = 1 g/mol, Oxygen = 16 g/mol.

Answer: Molar mass of H₂O = (2 × 1) + 16 = 18 g/mol

Question 4: Identify the safety precautions to consider when handling gases like sulphur dioxide (SO₂) in a laboratory setting.

Answer: Ensure proper ventilation, avoid inhaling the gas directly, wear safety goggles and gloves, and handle the gas in a fume hood.

Question 5: Which of the following molecules is a simple molecule? A) Sodium chloride (NaCl) B) Oxygen (O₂) C) Diamond (C) D) Silicon dioxide (SiO₂)

Answer: B) Oxygen (O₂)

Question 6: Fill in the blank: A molecule composed of two non-metal atoms sharing electrons is called a __________ molecule.

Answer: covalent

Question 7: Describe one real-world application of simple molecules in industry or daily life.

Answer: Water (H₂O) is used for drinking, cooking, and sanitation; carbon dioxide (CO₂) is used in carbonated drinks and fire extinguishers; methane (CH₄) is used as a fuel.

Question 8: Identify the variable factors in an experiment to determine the effect of temperature on the rate of formation of simple molecules like ammonia (NH₃).

Answer: Variables include temperature (independent variable), reaction time, concentration of reactants, and pressure.

Question 9: Explain why simple molecules tend to have low melting and boiling points compared to giant structures like metals or ionic lattices.

Answer: Because the intermolecular forces between simple molecules are weak compared to the strong covalent or ionic bonds in giant structures, requiring less energy to change state.

Question 10: Using the concept of molecular formulas, determine the molecular formula of a compound with 12 atoms of Carbon, 22 of Hydrogen, and 11 of Oxygen.

Answer: C₁₂H₂₂O₁₁