Question 1: Define covalent bonding and explain how it relates to the structure of diamond and graphite.

Answer: Covalent bonding is a type of chemical bond where atoms share pairs of electrons. In diamond, each carbon atom forms four strong covalent bonds in a tetrahedral structure, making it extremely hard. In graphite, each carbon atom forms three covalent bonds in layers with weak forces between layers, allowing it to be soft and slippery.

Question 2: Describe the difference in the bonding structure between diamond and graphite.

Answer: Diamond has a three-dimensional network of covalent bonds where each carbon is bonded to four others, creating a very rigid structure. Graphite has layers of carbon atoms bonded in a hexagonal pattern with three covalent bonds per atom, and the layers are held together by weak van der Waals forces.

Question 1: Calculate the molar mass of a single carbon atom and of diamond, which consists of 1 mole of carbon atoms.

Answer: Molar mass of carbon atom = 12.01 g/mol; Molar mass of diamond (1 mol of C) = 12.01 g/mol

Question 2: If a diamond has a density of 3.52 g/cm³ and a volume of 10 cm³, what is its mass?

Answer: Mass = Density × Volume = 3.52 g/cm³ × 10 cm³ = 35.2 g

Question 1: Describe a safe method to test the hardness of a sample of diamond and graphite.

Answer: To test hardness, gently scratch the sample with a known hard material like a steel file. Diamond will scratch most materials due to its high hardness, while graphite can be easily scratched or will leave a mark.

Question 2: A sample of graphite weighs 15 grams and has a volume of 5 cm³. Calculate its density and compare it to the density of diamond.

Answer: Density of graphite = Mass / Volume = 15 g / 5 cm³ = 3 g/cm³. Compared to diamond's density of 3.52 g/cm³, graphite is less dense.

Question 1: Explain why diamond is used in cutting tools and why graphite is used as a lubricant, based on their structures and properties.

Answer: Diamond's strong covalent bonds in a three-dimensional network give it exceptional hardness, making it ideal for cutting tools. In contrast, graphite's layered structure with weak forces between layers allows the layers to slide over each other easily, making it effective as a lubricant.

Question 1: Identify two industries where diamond's properties are utilized and explain why.

Answer: Diamonds are used in the jewelry industry for their brilliance and durability, and in cutting tools for their hardness in the manufacturing industry.

Question 2: Describe a technological application of graphite in electronics.

Answer: Graphite is used as an electrode material in batteries and electrolysis due to its good electrical conductivity and stability.