Writer four characteristic properties of p-block elements.

Explanation

### Step-by-Step Text Solution:

**Step 1: Definition of p-block elements**
P-block elements are found in groups 13 to 18 of the periodic table. They include a diverse range of elements, including metals, metalloids, and non-metals.

**Step 2: Characteristic Property 1 - Presence of Metals and Non-Metals**
P-block elements contain both metals and non-metals, but the number of non-metals is significantly higher than that of metals. This diversity contributes to a wide range of chemical properties.

**Step 3: Characteristic Property 2 - Metallic and Non-metallic Character**
The metallic character of p-block elements increases as you move down a group (top to bottom), while the non-metallic character increases as you move from left to right across a period. This trend is due to the increasing number of electron shells and electronegativity.

**Step 4: Characteristic Property 3 - Ionization Enthalpy**
The ionization enthalpy of p-block elements is generally higher than that of s-block elements. This is because p-block elements have higher electronegativity and require more energy to remove an electron.

**Step 5: Characteristic Property 4 - Formation of Covalent Compounds**
P-block elements predominantly form covalent compounds. Examples include boron trifluoride (BF3) and boron trichloride (BCl3), which are typical covalent compounds formed by these elements.

**Step 6: Characteristic Property 5 - Variable Oxidation States**
Many p-block elements exhibit variable oxidation states. For instance, sulfur can show oxidation states of -2, 0, +4, and +6, while halogens like fluorine typically have an oxidation state of -1.

### Summary of Characteristic Properties of p-block Elements:
1. Presence of both metals and non-metals, with a predominance of non-metals.
2. Increasing metallic character down a group and increasing non-metallic character across a period.
3. Higher ionization enthalpy compared to s-block elements.
4. Predominantly form covalent compounds.
5. Exhibit variable oxidation states.

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