Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.
Answer:
H₃PO₄ is an acid because donates the proton to fenolate.
Fenolate is the base because accepts the proton from the acid.
Explanation:
Bronsted theory mentioned that acid is the one that donates a proton to another compound and base is the one that receives it.
H₃PO₄ + C₆H₅O⁻ ⇄ H₂PO₄⁻ + C₆H₅OH
acid base conj. base conj. acid
H₃PO₄ is an acid because donates the proton to fenolate.
Fenolate is the base because accepts the proton from the acid.
If we follow the dissociation, the diacid phosphate can donate two more protons, it is still a Bronsted acid, but it can act as an acid or a base. This is called amphoteric.
D is the answer since it is changing the element.
Oxygen gas was most likely absent from Earth's primitive atmosphere. The current theory is that the Earth's early atmosphere was composed of mainly carbon dioxide and methane due to the high volcanic activity. Cyanobacteria and their use of photosynthesis was what caused earth's atmosphere to become oxygen enriched.
I hope that helps.
