What is the [H+] when the pH is 4.2? Group of answer choices

A) 6.3x10^-5

B) 9.8

C) 1.6x10^-10

D) 1.6x10^4

pls give a little context, so I know how you got the answer :)

african americans demonstrated their newly found freedom by relocating often in search of relatives whom they had been separated from during slavery. others established schools to educate freed people and they built institutions such as churches and political organizations to advocate for their rights.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

i'm pretty sure it is letter c.) car