What is the modern Periodic table Based on? Select all that apply. A. atomic number
B. atomic mass
C. oxidation number
D. valence electrons
E. electron configuration

The answer(s) is A and E.

idk i’m struggling too

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.