Slope slōp/ noun 1. a surface of which one end or side is at a higher level than another; a rising or falling surface. a difference in level or sideways position between the two ends or sides of a thing. synonyms: gradient, incline, angle, slant, inclination, pitch, decline, ascent, declivity, rise, fall, tilt, tip, downslope, upslope, grade, downgrade, upgrade "the slope of the roof" a part of the side of a hill or mountain, especially as a place for skiing. synonyms: hill, hillside, hillock, bank, sidehill, escarpment, scarp; More verb 1. (of a surface or line) be inclined from a horizontal or vertical line; slant up or down. synonyms: slant, incline, tilt; More
<em>B. Methyl yellow, which changes from yellow to red around a pH of
</em>
<em>4.0</em>
Explanation:
A pH indicator is a technique by which the pH of a solution can be known. The scenario in the question describes that the scientist wants to determine a pH after it gets converted from 6 to below 4. For this recognition, the scientist should use a methyl yellow indicator which will change from yellow to red once a pH around 4 is achieved.
You find this by taking the total distance of the first lap and doubling it. You could also find it by adding 400 meters to 400 meters, which would total at 800 meters
