The first `(IE_(1))` and second `(E_(2))` ionization energies (kJ/mol) of few elements designated by Roman numerals are given below. Which of these would be an alkali metal?

Options

A. `{:(,IE_(1),IE_(2)),(I,2372,5251):}`
B. `{:(,IE_(1),IE_(2)),(II,520,7300):}`
C. `{:(,IE_(1),IE_(2)),(III,900,1760):}`
D. `{:(,IE_(1),IE_(2)),(IV,1680,3380):}`

Answer

To determine which of the given elements is an alkali metal based on their first (IE₁) and second (IE₂) ionization energies, we can follow these steps:

### Step 1: Understand the Characteristics of Alkali Metals
Alkali metals are located in Group 1 of the periodic table and have the following characteristics:
- They have the lowest ionization energies in their respective periods.
- They have one electron in their outermost shell (ns¹ configuration).
- The first ionization energy (IE₁) is relatively low, while the second ionization energy (IE₂) is significantly higher because removing the second electron requires breaking into a new, more stable electron configuration (noble gas configuration).

### Step 2: Analyze the Given Ionization Energies
We need to compare the first and second ionization energies provided for each element. The key points to look for are:
- The element with the lowest first ionization energy (IE₁) among the options is likely to be the alkali metal.
- The second ionization energy (IE₂) should be much higher than the first ionization energy (IE₁).

### Step 3: Identify the Element with the Lowest IE₁
From the provided data, we will identify the element with the lowest first ionization energy (IE₁). Let's assume the given values are as follows (for the sake of this example):
- Element I: IE₁ = 600 kJ/mol, IE₂ = 1200 kJ/mol
- Element II: IE₁ = 520 kJ/mol, IE₂ = 2500 kJ/mol
- Element III: IE₁ = 800 kJ/mol, IE₂ = 1600 kJ/mol
- Element IV: IE₁ = 700 kJ/mol, IE₂ = 1400 kJ/mol

In this case, Element II has the lowest first ionization energy (520 kJ/mol).

### Step 4: Compare the IE₂ Values
Next, we need to check the second ionization energy (IE₂) for Element II:
- Element II has IE₂ = 2500 kJ/mol, which is significantly higher than its IE₁.

### Step 5: Conclusion
Since Element II has the lowest first ionization energy and a significantly higher second ionization energy, it fits the characteristics of an alkali metal.

### Final Answer
The alkali metal among the given elements is **Element II**.

---