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.
Fe needs to have a positive charge of +3 to balance out -3 Cl
it's the first one. the one with ox in it
Benzene at the same prssure ie the horizontal dotted line, benzene requires the minimal temperature hence its most volatile
Properties: melting point of -100.98°C
boiling point of 34.6°C
density of 3.214 g/l
gravity of 1.56 (-33.6°C)
valence of 1, 3, 5, or 7
