Explain the levels of classification and how it can be used to determine the relatedness of organisms

What element is able to combine with itself and hydrogen to form large molecules ?

Aresearcher created three groups based on participants bmi: normal weight, overweight and obese. the hypothesis being tested is that the three groups differ in the mean number of artificially sweetened drinks consumed weekly. which statistical test might the researcher use, assuming a reasonably normal distribution of values.

Describe surface tension in a group of bonded water molecules