Question

Electron gain enthalpy values of noble gases are positive because:

A. They have smallest size
B. They are monoatomic
C. They have stable electronic configuration
D. They are all gases

Answer 1

The electron gain enthalpy values of noble gases are positive because they have filled outer subshells, making them stable and unlikely to gain additional electrons. This is because the addition of an electron would result in a loosely bound electron, which is energetically unfavorable. Noble gases form compounds only under specific conditions of high pressure and temperature.

Step-by-step explanation:

The electron gain enthalpy values of noble gases are positive because they are all gases and have filled outer subshells, making them particularly stable. Due to their stability, noble gases have large ionization energies and do not readily give up an electron. Furthermore, if a noble gas were to accept an extra electron, it would be in a significantly higher energy level and thus loosely bound. This makes it energetically unfavorable for noble gases to gain additional electrons, resulting in positive electron gain enthalpy values.

Chemical reactions often involve the sharing of electrons. Noble gases, with their stable electron configurations, do not readily participate in chemical reactions and form compounds only under high pressure and temperature. Therefore, their electron gain enthalpy values are positive because the addition of an electron is energetically unfavorable for them.