Experiments are often replicated or repeated even when no obvious mistake was visible. This is to establish how variable results are. Statistically, multiple runs are used to determine the variance or standard deviation around the average value. The best answer for this is choice C, to double check results.
Physical science is concerned with the inorganic world, including physics, astronomy, certain types of chemistry, and generally, earth sciences. If it includes non-living things, it is physical science.
Graphite is well known to be pencil lead - You might actually learn this in Chemistry/Physical Science like we did!
Charcoal & coal you cannot use - you could but it'd be difficult and irritating.
Fullerene is the third form of carbon. It can be used for electronics AND medicine. Amazing right??
Some characteristics that is shared is a soft body and an outer shell to protect their body.
