The pH of a sample of lake water was originally 6 when measured in 1987. When measured again in 2014, the pH of the water was 4. How has the concentration of hydrogen ions in the lake changed?

1. The concentration of hydrogen ions has increased by a factor of 2.
2. The concentration of hydrogen ions has increased to 10 times its original value.
3. The concentration of hydrogen ions has increased to 100 times its original value.
4. The concentration of hydrogen ions has decreased by a factor of 2.

as we probably am aware that our atmosphere or air have various levels, each level has different gasses, and each gas has another porousness. at the point when the light originates from lower porousness to higher penetrability, it alters its course. with the goal that implies that when the light originates from the moon to the earth, it alters it's course a lot more occasions. it essentially implies that the state of the light piece of the moon is changed on the earth.

not copied too! hope this !

joke:

h o h o hope you have a merry christmas!

e/c, where e is its total energy