A is the correct answer from what i understand in this question
Answer:
The vertical columns (group) of the periodic table are arranged such that all it's elements have the same number of valence electrons. All elements within a certain group thus group share similar properties.
Answer:
B). Allow efficient gathering of unobservable phenomena.
Explanation:
Surveys are described as the method of gathering information from a specified group of respondents for purposes like research or assessment of the truth of thoughts or opinions associated with a process.
As per the question, one of the most considerable benefits of the survey is that 'it allows the efficient gathering of unobservable phenomena'. The data associated with phenomena like stated preferences, behaviors, beliefs, and factual information are unobservable and can not be collected through observation but surveys help in doing so as well as in the assessment of the validity or reliability of the existing propositions about such phenomena. Thus, <u>option B</u> is the correct answer.
Answer:
A. Soaps react with ions in hard water to create a precipitate.
B. Soaps are both hydrophobic and hydrophilic.
D. Soaps should be weakly alkaline in solution.
Explanation:
A. Hard water contains <u>magnesium and calcium minerals</u> like calcium and magnesium carbonates, sulfates and bicarbonates. As soon as these minerals come in contact with soap their ions like Mg²⁺ & Ca²⁺ form precipitates.
B. Soap are both hydrophilic and hydrophobic. They reason why they exhibit both the properties is really important for their functionality. The hydrophobic part of soap makes interaction with oil/dust particles while the hydrophilic part makes interaction with water. When the cloth is rinsed the dirt/soap particles are removed from the dirty clothes thereby making them clean.
C. Soaps have alkaline pH i.e. more than 7 that is why they have bitter taste.
D) Chlorine, Cl. Hope that helped
