When we perform a study, we test a specific hypothesis to see whether our hypothesis is supported by the data or not. If our hypothesis is not supported by the data, then we can argue that a specific argument (that would be important for this hypothesis) does not have a claim in scientific research.
This is more broadly meant though. Usually you need to perform multiple studies and test multiple hypothesis to be able to critique a scientific argument and see whether the claims it makes and the predictions it makes hold up in scientific research.
Answer:
1. Condensation
I... am not sure for the rest :( I am so sorry
Scarlet fever was discovered in 1827, I believe
