The focused research question for this practical investigation is: How many carbon atoms are there in your pencil signature on a piece of paper? Plan, carry out and evaluate a methodology based on mass measurements.
## Guidance
- You will need access to an analytical electronic balance with a high sensitivity.
- Find out how pencils are classified into different grades using the letters H and B and choose a pencil that has the highest percentage of carbon in the form of graphite.
- It will take a large number of signatures on a single sheet of paper to get a measurable change in mass.
- Use the concept of ratios to scale down 12.01 g (mass of one mole of carbon atoms and equivalent to the relative atomic mass of 12.01) and 6.02×1023 g mol−1 to the mass of a single signature.