Which of the element is expected to have lowest first ionisation enthalpy

Options

A. Sr
B. Al
C. Xe
D. S.

Explanation

To determine which element is expected to have the lowest first ionization enthalpy among the given options (tronsium, aluminium, xenon, and subcar), we can follow these steps:

### Step 1: Understand Ionization Enthalpy
Ionization enthalpy (or ionization energy) is the energy required to remove an electron from the outermost shell of a gaseous atom. Generally, the lower the ionization enthalpy, the easier it is to remove an electron.

**Hint:** Remember that ionization energy is influenced by the atomic structure and the position of the element in the periodic table.

### Step 2: Identify the Elements
- **Tronsium (Sr)**: An alkaline earth metal located in Group 2.
- **Aluminium (Al)**: A post-transition metal located in Group 13.
- **Xenon (Xe)**: A noble gas located in Group 18.
- **Subcar (C)**: A non-metal located in Group 14.

**Hint:** Group classification helps to predict trends in ionization enthalpy.

### Step 3: Analyze the Periodic Trends
- **Tronsium (Sr)**: Being in Group 2, it has a larger atomic radius and lower effective nuclear charge compared to elements on the right side of the periodic table. Thus, it has a lower ionization energy.
- **Aluminium (Al)**: Has a higher ionization energy than tronsium due to its position in Group 13.
- **Xenon (Xe)**: As a noble gas, it has a high ionization energy because its outer shell is full, making it stable and less likely to lose an electron.
- **Subcar (C)**: Also has a higher ionization energy compared to tronsium due to its smaller atomic size and higher effective nuclear charge.

**Hint:** Remember that as you move from left to right across a period, ionization energy generally increases.

### Step 4: Compare the Elements
Based on the positions of these elements in the periodic table:
- Tronsium has the largest atomic size and the lowest effective nuclear charge among the options, making it the easiest to ionize.
- The other elements (Al, Xe, and C) have higher ionization energies due to their smaller sizes and greater effective nuclear charge.

**Hint:** Compare the atomic sizes and effective nuclear charges to determine which element will have the lowest ionization energy.

### Conclusion
From the analysis, **tronsium (Sr)** is expected to have the lowest first ionization enthalpy among the given elements.

**Final Answer:** Tronsium (Sr) has the lowest first ionization enthalpy.

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