Question 1: Define an isotope and explain how isotopes of the same element differ from each other.

Answer: An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons. Isotopes of the same element differ in their atomic mass but have similar chemical properties.

Question 2: Describe one way in which isotopes are used in nanotechnology.

Answer: Isotopes are used in nanotechnology for tracking and imaging at the nanoscale, such as using radioactive isotopes to monitor the movement of nanoparticles.

Question 3: What is the main difference between a stable isotope and a radioactive isotope?

Answer: A stable isotope does not decay over time, while a radioactive isotope undergoes decay, emitting radiation.

Question 4: In a sample of aluminium, which isotope is most abundant: Aluminium-27 or Aluminium-26? Justify your answer based on common isotope stability.

Answer: Aluminium-27 is most abundant because it is a stable isotope, whereas Aluminium-26 is radioactive and less common in nature.

Question 5: Calculate the relative atomic mass of an element that has 75% of its atoms as isotope A (mass number 20) and 25% as isotope B (mass number 22).

Answer: Relative atomic mass = (0.75 × 20) + (0.25 × 22) = 15 + 5.5 = 20.5

Question 6: Identify the variables that need to be controlled in an experiment measuring the radioactive decay of isotopes in nanomaterials.

Answer: Variables such as temperature, radiation exposure, sample purity, and measurement time should be controlled to ensure accurate results.

Question 7: A nanotech lab uses a radioactive isotope with a half-life of 24 hours. How much of a 10 g sample remains after 48 hours?

Answer: Remaining amount = 10 g × (1/2)^(48/24) = 10 g × (1/2)^2 = 10 g × 1/4 = 2.5 g

Question 8: Explain how isotopic analysis can assist in improving the precision of nanomaterial manufacturing.

Answer: Isotopic analysis allows scientists to track the origin and composition of nanomaterials at the atomic level, leading to better quality control and more precise manufacturing processes by identifying impurities or inconsistencies based on isotopic signatures.

Question 9: What safety precautions should be considered when working with radioactive isotopes in a nanotechnology research setting?

Answer: Safety precautions include wearing protective clothing, using shielding to minimise radiation exposure, working within designated areas, and following proper disposal procedures for radioactive waste.

Question 10: Discuss one ethical consideration related to the use of radioactive isotopes in nanotechnology applications.

Answer: One ethical consideration is ensuring that the use of radioactive isotopes does not pose health risks to humans or the environment, and that their use complies with safety regulations and ethical standards.