Question

Ph scale
Which on is true
A substance with ph is twice as acidic as substance with ph of 4.
A subtances with ph 3 is 10 as acidic as substance with ph of 4.
A substance with ph 3 twice as alkies as substances with ph 4.
a substancs with ph 3 10 time alkies as substance with ph 4.
it was my test question
i don't remember complete sentences.
plz help.

Answer 1

i know about ph scale but still could not undersatand this question .