An ion has 38 protons, 36 electrons, qnd 40 neutrons, what is its mass #?

Strontium - 38 (atomic #)

Explanation:

An ion with 38 protons, 36 electrons, and 40 electrons is Strontium. Strontium's atomic number is 38.

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.