JEE MainChemistryClassification of Elements and Periodicity in Properties
Consider four elements P, Q, R, and S belonging to the third period of the periodic table. P has the lowest first ionization enthalpy in the period, Q has the most negative electron gain enthalpy, R forms an amphoteric oxide, and S has a positive electron gain enthalpy. Identify the INCORRECT statement regarding the properties of these elements.
Options
- AP and Q are highly reactive, while S is the least reactive element among them.
- BThe chemical reactivity steadily increases from P to Q across the period.
- CThe oxide formed by P is basic in nature, whereas the oxides formed by Q are acidic.
- DThe high reactivity of P is due to its low ionization enthalpy, while that of Q is due to its highly negative
Correct answer
B. The chemical reactivity steadily increases from P to Q across the period.
Step-by-step solution
Based on the given properties for the third period elements: P has the lowest first ionization enthalpy, so it is Sodium (Na, Group 1). Q has the most negative electron gain enthalpy, so it is Chlorine (Cl, Group 17). R forms an amphoteric oxide, so it is Aluminium (Al, Group 13). S has a positive electron gain enthalpy, so it is Argon (Ar, Group 18). Chemical reactivity across a period is highest at the extremes (Group 1 and Group 17) due to the ease of losing and gaining electrons, respectively. It is lowest in t