Dr Mano is a researcher who thinks that the poor performance of the students at his school is due to excessive alcohol intake. What scientific steps can he take to best study his assumptions​

to design an experiment aimed at testing the null hypothesis. Finally, it is required to apply a statistical measure in order to reject or accept the null hypothesis

Explanations:

The scientific method consists in the first place in posing a question that can be used to explain an observation from the real world. This question needs to be subsequently explained by a working hypothesis. In this case, the working hypothesis may be "the poor performance of the students is associated with alcohol intake". Then, it is required to design an experiment in order to confirm or reject the null hypothesis. In this case, the null hypothesis would state that there is no relationship between both groups. The further experiment would consist of testing the performance of the students that consume alcohol versus students that don't consume alcohol. Finally, the results obtained from the experiment must be analyzed by using a statistical measure such as, for example, the p-value, which enables to accept/reject the null hypothesis by assessing the significance level of the results.

they float because they are less dense than the water itself

something denser than water, like a rock, will sink to the bottom

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.