[Solved] In drawing the Lewis structure for an organic compound, the carbon atoms should always be shown with eight total electrons. Two-Tail: A term used in statistics referring to the two-tailed test of significance that checks for the possibility of positive or negative differences. Observations: The act of noting and recording something with instruments or the naked eye as part of a scientific or empirical study. Untreated Population: A group in a study or an experiment that does not receive the treatment or intervention being tested. Significance Level: The threshold in hypothesis testing that determines the probability of rejecting the null hypothesis when it is actually true, often denoted by alpha.