QJEEM16Ch3226: JEE Main 2016 Chemistry - Class 11 JEEM16Ch3226 Solution: Which of the following atoms has the highest first ionization…
Multiple Choice Options
- A Na
- B K
- C Sc
- D Rb
Step-by-Step Verified Solution
The first ionization energy is the energy required to remove the most loosely held electron from an atom or a cation. It is measured in units of electron volts (eV) or kilojoules per mole (kJ/mol).
Among the given options, Scandium (Sc) has the highest first ionization energy because it has the smallest atomic radius and the highest nuclear charge. As we move from left to right across a period in the periodic table, the atomic radius decreases while the nuclear charge increases. This results in a stronger attraction between the positively charged nucleus and the negatively charged electrons in the outermost energy level, which requires more energy to remove the most loosely held electron.
The first ionization energy of the given options in increasing order is:
Na < K < Rb < Sc
Therefore, Scandium (Sc) has the highest first ionization energy among the given options.