Which of the following statement is true about the elements of IA and IIA group elements?

Options

A. The IE of alkali metals are higher than that of alkaline earth metal
B. The size of alkaline earth metals are larger than that of alkali metals
C. The reactivity of alkaline earth metals is less than that of alkali metals
D. All the above

Answer

To determine which statement is true about the elements of Group IA (alkali metals) and Group IIA (alkaline earth metals), we will analyze the given statements one by one.

### Step-by-Step Solution:

1. **Understanding Group IA and IIA Elements**:
- Group IA elements are known as alkali metals (e.g., Lithium (Li), Sodium (Na), Potassium (K)).
- Group IIA elements are known as alkaline earth metals (e.g., Beryllium (Be), Magnesium (Mg), Calcium (Ca)).

2. **Analyzing the Statements**:
- **Statement 1**: "The ionization energy of alkali metals is higher than that of alkaline earth metals."
- **Analysis**: Alkali metals have a single electron in their outermost shell, making it easier to lose that electron compared to alkaline earth metals, which have two. Thus, alkali metals generally have lower ionization energies than alkaline earth metals. This statement is **false**.

- **Statement 2**: "The size of alkaline earth metals is larger than that of alkali metals."
- **Analysis**: As we move down a group in the periodic table, the atomic size increases. However, comparing elements in Group IA and IIA, alkali metals are generally larger than alkaline earth metals due to their fewer protons and a single outer electron. This statement is **false**.

- **Statement 3**: "The reactivity of alkaline earth metals is less than that of alkali metals."
- **Analysis**: Alkali metals are more reactive than alkaline earth metals because they can easily lose their single valence electron to form cations. Alkaline earth metals, on the other hand, require more energy to remove two electrons. This statement is **true**.

3. **Conclusion**:
- The correct statement is: "The reactivity of alkaline earth metals is less than that of alkali metals."

### Final Answer:
The true statement about the elements of Group IA and IIA is: "The reactivity of alkaline earth metals is less than that of alkali metals."

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