I think its the first 1 C i remember answering this question on my school work
The concentration of hydronium ions equals that to hydroxide ions the answer is A) pH is equal tot he negative log of hydrogen. the pH of water is 7 which equal to 10^-7 of H+ and OH- ions.
There are *219,000* hours in 25 years
A. about 14 days
EXPLANATION
It takes 27.5 days for the moon to orbit the Earth, so a solar eclipse and a lunar eclipse can never take place less than about two weeks apart.
For solar eclipse, the moon must be in between Sun and Earth. And every one knows full moon and new moon can't happen same day.
