Answer:
The need for continental time zones stemmed directly from the problems of moving passengers and freight over the thousands of miles of rail line that covered North America by the 1880s. Since human beings had first begun keeping track of time, they set their clocks to the local movement of the sun.
Mannan-oligosaccharides (MOS) are prebiotics composed of complex carbohydrate molecules, derived from the outer cell wall of S. cerevisiae, whose main components, β-glucans (mannoproteins), are known as elements capable of activating the immune system of animals [3, 5]. :D
this is the answer pls mark me as the brainliest
Explanation:
Hydrogen atoms contain 1 proton and 1 electron while being devoid of neutrons. When they lose their electron they form an ion or H+, a particle carrying a unit of positive charge. pH measures how basic or acidic a water-based solutions are, with a formula for pH is
pH = -log[H+].
...where pH is -base 10 log of the concentration of hydrogen ions within the solution.
Initial volume= 20 mL
Final volume= 600 mL
# of dilutions=
= 30
for a pH 2= [H+]= 
∴ [H+]= 
and pH is an antilog of [H+]= - log 
∴pH = 3.47
Learn more about pH at brainly.com/question/4981491
Learn more about pKA at brainly.com/question/11062486
#LearnWithBrainly