The decreasing order of basic character of `K_(2)O` BaO , CaO and MgO is

Options

A. `K_(2)O gt BaO gt CaO gt MgO`
B. `K_(2)O gt CaO gt BaO gt MgO`
C. `MgO gt BaO gt CaO gt K_(2)O`
D. `MgO gt CaO gt BaO gt K_(2)O`

Explanation

To determine the decreasing order of basic character of K₂O, BaO, CaO, and MgO, we need to understand the basicity of metal oxides, particularly those of alkali and alkaline earth metals.

### Step-by-Step Solution:

1. **Identify the Oxides**: We have four oxides to consider: K₂O (Potassium Oxide), BaO (Barium Oxide), CaO (Calcium Oxide), and MgO (Magnesium Oxide).

2. **Understand Basicity**: Basicity of metal oxides generally increases with the electropositivity of the metal. Alkali metals (Group 1) are more electropositive than alkaline earth metals (Group 2). Therefore, alkali metal oxides are generally more basic than alkaline earth metal oxides.

3. **Rank the Alkali Metal Oxide**: K₂O is an alkali metal oxide. As an alkali metal oxide, it is expected to be the most basic among the four oxides.

4. **Rank the Alkaline Earth Metal Oxides**: Among BaO, CaO, and MgO:
- Barium (Ba) is below Calcium (Ca) in the periodic table, and Strontium (Sr) is not considered here.
- The basicity increases down the group in alkaline earth metals due to increasing electropositivity. Therefore, BaO > CaO > MgO.

5. **Combine the Rankings**:
- From the previous steps, we have:
- K₂O (most basic)
- BaO (next)
- CaO
- MgO (least basic)

6. **Final Order**: Thus, the decreasing order of basic character is:
- K₂O > BaO > CaO > MgO

### Conclusion:
The correct answer is **K₂O > BaO > CaO > MgO**.