`Be(IIA)` shows different behaviour as compared to other elements of the same group the reason is

Options

A. Small size and high electronegativity
B. Small size and low electronegativity
C. Bigger size and low ionization energy
D. Bigger size and large ionic radius

Answer

To understand why Beryllium (Be) shows different behavior compared to other elements in the same group (Group IIA), we can analyze the properties of Beryllium and compare them with those of other alkaline earth metals. Here’s a step-by-step breakdown of the reasoning:

### Step 1: Identify the Group
Beryllium is in Group IIA of the periodic table, which includes elements like Magnesium (Mg), Calcium (Ca), Strontium (Sr), and Barium (Ba).

**Hint:** Recall that elements in the same group typically exhibit similar chemical properties.

### Step 2: Compare Atomic Size
Beryllium has a smaller atomic size compared to other alkaline earth metals. The atomic radius increases as you move down the group due to the addition of electron shells.

**Hint:** Consider how atomic size affects the properties of elements, particularly their ability to form bonds.

### Step 3: Electronegativity
Beryllium has a higher electronegativity compared to other elements in Group IIA. Electronegativity is a measure of an atom's ability to attract and hold onto electrons.

**Hint:** Think about how electronegativity influences the type of bonds an element can form.

### Step 4: Ionization Energy
Beryllium has a higher ionization energy than the other alkaline earth metals. This means it requires more energy to remove an electron from a beryllium atom compared to its heavier counterparts.

**Hint:** Reflect on how ionization energy affects the reactivity of elements.

### Step 5: Absence of Vacant D Orbitals
Beryllium does not have vacant d orbitals in its valence shell, which limits its ability to form complex ions or exhibit variable oxidation states, unlike heavier alkaline earth metals.

**Hint:** Consider how the presence or absence of d orbitals can influence the chemistry of an element.

### Conclusion
Based on the above points, Beryllium's small size and high electronegativity, along with its unique electronic configuration, lead to its distinct behavior compared to other elements in Group IIA. Therefore, the correct answer to the question is:

**Answer: A, small size and high electronegativity.**