Group 18 Elements

Step 1: Concept
Neil Bartlett noticed the similarity between Oxygen and Xenon properties.
Step 2: Analysis
The first ionization energy of ( ) is very close to that of ( ). Their molecular/atomic diameters are also nearly identical.
Step 3: Conclusion
Due to comparable sizes and ionization energies, was expected to react similarly to .
Final Answer: (D)

Step 1: Origin
-decay is a nuclear phenomenon, not an atomic one involving electron orbits.
Step 2: Mechanism
It occurs when a neutron in an unstable (radioactive) nucleus transforms into a proton, emitting an electron (beta particle) and an antineutrino.
Step 3: Conclusion
The electron originates from the radioactive nucleus itself.
Final Answer: (d)