Neko and or Nay Nay can you please talk to me??

There is one girl i like and i don't know how to tell her that, i have a feeling she knows but if she doesn't i don't want to make a fool out of myself how is one way to boost my confidence on asking her out

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Why is it possible for different microorganisms to extract energy not only from carbohydrates and other biological molecules but from a large variety of substances?