Which of the following is true about elements?
elements can combine into compounds with new properties
elements only combine with other elements of the same type to form compounds.
elements can be broken down into different types of atoms.
elements are made of compounds with different properties.

The first one

Explanation:

Elements are as simple as it gets

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.

the increase of protons   hope this