Scientists know that pure Water is neutral and has a pH of 7. Acids have a pH lower than 7 and bases have a pH higher than 7. To find the pH level of a liquid scientists use the equation pH = -log(H+) where H is the hydrogen ion concentration in moles per
Liter
What is the hydrogen ion concentration of an base solution with a pH of 9?
A)
-10° moles per liter
B)
-10-9 moles per liter
10-moles per liter
D)
109 moles per liter

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

125 yards

step-by-step explanation:

i take 75 plus 50.