Arrange the following elements in increasing order of first ionization enthalpy: Li, Be, B, C, N
Choose the correct answer from the options given below:
Explanation:
Ionization enthalpy generally increases across a period from left to right. However, there are exceptions due to electronic configurations.
1. Lithium (Li): It has the lowest ionization enthalpy as it readily loses one electron to achieve a stable noble gas configuration.
2. Boron (B): Boron has a slightly lower ionization enthalpy than beryllium because removing a p-electron from boron is easier than removing an s-electron from the filled s-orbital of beryllium.
3. Beryllium (Be): Beryllium has a higher ionization enthalpy than lithium due to its smaller size and higher effective nuclear charge. Also it has a completely filled 2s orbital.
4. Carbon (C): Carbon has a higher ionization enthalpy than boron due to its increased nuclear charge and smaller atomic radius.
5. Nitrogen (N): Nitrogen has an exceptionally high ionization enthalpy because it has a half-filled p-orbital configuration (2p³), which is particularly stable. Removing an electron disrupts this stable configuration.
Therefore, the increasing order of first ionization enthalpy is:
Li < B < Be < C < N
Conclusion:
The correct order is Li < B < Be < C < N
List I (Spectral Lines of Hydrogen for transitions from) | List II (Wavelength (nm)) | ||
A. | n2 = 3 to n1 = 2 | I. | 410.2 |
B. | n2 = 4 to n1 = 2 | II. | 434.1 |
C. | n2 = 5 to n1 = 2 | III. | 656.3 |
D. | n2 = 6 to n1 = 2 | IV. | 486.1 |
The following diagram shown restriction sites in E. coli cloning vector pBR322. Find the role of ‘X’ and ‘Y’gens :