pH 2 is very acidic. That is pretty near the pH of Lemon Juice. Low pHs under 7 are very acidic. The further you go from 7 downwards, the more acidic the substance.
A car battery has a pH of -0.7 which is under 1 or even 0. There are not that many substances around with that low a Ph.
Anything below 7 is acidic, and anything above 7 is basic. 7 itself is a neutral solution. Each level you go down is 10 times more acidic than the one above.
