The dihydrogenphosphate ion, H2PO4− is amphiprotic. In which of the following reactions is this ion serving as a base?

H3O+(aq) + H2PO4−(aq) ⇌ H3PO4(aq) + H2O(l)
H3O+(aq) + HPO42−(aq) ⇌ H2PO4−(aq) + H2O(l)
H3PO4(aq) + HPO42−(aq) ⇌ 2 H2PO4−(aq)

H3PO4(aq) + HPO42-(aq) ⇄ 2H2PO4-

Explanation:

In the reaction of Phosphonic acid, H3PO4 one proton H+ is removed to form dihydrogen phosphate ion, H2PO4-, which is a base.

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.