Elements of which block in modern periodic table cannot have-ve oxidation state?

Options

A. `s`
B. `d`
C. `p`
D. None of these

Answer

To determine which block of elements in the modern periodic table cannot have negative oxidation states, we can analyze each block systematically.

### Step 1: Identify the Blocks of the Periodic Table
The modern periodic table is divided into four main blocks:
- **s-block**: Groups 1 and 2 (alkali metals and alkaline earth metals)
- **p-block**: Groups 13 to 18 (includes non-metals and some metals)
- **d-block**: Transition metals (Groups 3 to 12)
- **f-block**: Lanthanides and actinides

**Hint**: Remember the classification of elements into blocks based on their electron configurations.

### Step 2: Analyze the s-block Elements
The s-block consists of:
- **Alkali Metals (Group 1)**: These elements have a +1 oxidation state.
- **Alkaline Earth Metals (Group 2)**: These elements have a +2 oxidation state.

Both groups primarily exhibit positive oxidation states because they tend to lose electrons.

**Hint**: Focus on the common oxidation states of the elements in each block.

### Step 3: Analyze the d-block Elements
The d-block elements are known as transition metals. They exhibit variable oxidation states, ranging from 0 to +7. Some transition metals can also show negative oxidation states, but this is less common.

**Hint**: Transition metals are known for their ability to exhibit multiple oxidation states.

### Step 4: Analyze the p-block Elements
The p-block elements include a variety of non-metals and metalloids. Many non-metals in this block can exhibit negative oxidation states. For example:
- Nitrogen in ammonia (NH3) has a -3 oxidation state.
- Sulfur in hydrogen sulfide (H2S) has a -2 oxidation state.

**Hint**: Non-metals in the p-block are more likely to gain electrons, leading to negative oxidation states.

### Step 5: Conclusion
From the analysis:
- **s-block elements** (alkali and alkaline earth metals) cannot have negative oxidation states because they only exhibit positive oxidation states.
- **d-block elements** can show both positive and some negative oxidation states, but it is less common.
- **p-block elements** can exhibit both negative and positive oxidation states.

Thus, the elements that cannot have negative oxidation states are found in the **s-block** (Groups 1 and 2).

**Final Answer**: The elements of the **s-block** in the modern periodic table cannot have negative oxidation states.