The element with atomic number $Z = 117$ should:

Given below are two statements:
Statement $I$: The number of pairs among $[Al_2O_3, Cr_2O_3]$, $[Cl_2O_7, Mn_2O_7]$, $[Na_2O, V_2O_3]$ and $[CO, N_2O]$ that contain oxides of same nature (acidic, basic, neutral or amphoteric) is $4$.
Statement $II$: Among $Na_2O, Al_2O_3, CO$ and $Cl_2O_7$, the most basic and acidic oxides are $Na_2O$ and $Cl_2O_7$, respectively.

$Li$ resembles $Mg$ due to diagonal relationship which is attributed to

The correct sequence of acidic character is:

Which elements of a group show anomalous behaviour? Explain with examples.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A :$ Metallic character decreases and non-metallic character increases on moving from left to right in a period.
Reason $R :$ It is due to increase in ionisation enthalpy and decrease in electron gain enthalpy,when one moves from left to right in a period.
In the light of the above statements,choose the most appropriate answer from the options given below :