Question 1: Briefly describe what fullerenes are and how their structure differs from graphene.

Answer: Fullerenes are spherical or ellipsoidal molecules composed entirely of carbon atoms arranged in pentagons and hexagons, resembling a soccer ball. Graphene is a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice.

Question 2: Explain why the high surface area of graphene makes it useful in forensic detection methods.

Answer: The high surface area of graphene allows it to adsorb more chemical substances, making it highly sensitive for detecting trace amounts of drugs, toxins, or other chemicals in forensic samples.

Question 3: In forensic science, how can fullerenes be used to identify substances at a crime scene?

Answer: Fullerenes can be functionalized to bind specific molecules, enabling the detection of chemical residues or biological substances unique to a crime scene.

Question 4: Calculate the approximate surface area of a single graphene sheet measuring 1 cm by 1 cm. (Given: area = length × width)

Answer: 1 cm × 1 cm = 1 cm^2

Question 5: If a fullerene molecule has a diameter of approximately 0.7 nm, estimate its surface area assuming it's spherical. Use the formula for the surface area of a sphere: 4πr^2. (Note: r = diameter/2)

Answer: Radius r = 0.7 nm / 2 = 0.35 nm = 0.35 × 10^-9 m Surface area = 4π(0.35 × 10^-9 m)^2 ≈ 4 × 3.1416 × 1.225 × 10^-19 m^2 ≈ 1.54 × 10^-18 m^2

Question 6: Identify two safety precautions that should be taken when handling nanomaterials like fullerenes and graphene in a laboratory setting.

Answer: Wear appropriate gloves and a lab coat to prevent skin contact; use a fume hood to avoid inhalation of airborne particles.

Question 7: Describe a simple experimental approach to test the adsorption properties of graphene for organic molecules.

Answer: A possible experiment involves exposing a known quantity of graphene to a solution containing organic molecules, then measuring the concentration of molecules remaining in the solution after a set period using spectrophotometry. This assesses graphene's ability to adsorb the molecules based on changes in concentration.

Question 8: In a forensic scenario, a sample suspected to contain trace amounts of a drug is analyzed using graphene-based sensors. If the sensor detects a signal that is 50 times stronger than the baseline, what does this imply about the sample?

Answer: The strong signal suggests a high concentration of the drug or chemical in the sample, indicating its presence at detectable levels.

Question 9: Explain how the unique electrical properties of graphene contribute to its use in forensic detection devices.

Answer: Graphene's high electrical conductivity and sensitivity to chemical interactions make it ideal for sensors that detect minute amounts of substances through changes in electrical signals.

Question 10: A forensic scientist needs to identify a complex mixture of chemicals using nanomaterials. Which nanomaterial—fullerene or graphene—would be more suitable for creating a broad-spectrum detection device, and why?

Answer: Graphene would be more suitable because of its large surface area, excellent electrical properties, and ability to functionalize for detecting a wide range of chemicals.