To determine which element has the highest electronegativity, we need to understand the concept of electronegativity and how it varies across the periodic table.
### Step-by-Step Solution:
1. **Understanding Electronegativity**:
- Electronegativity is defined as the tendency of an atom to attract shared electrons in a chemical bond. The higher the electronegativity, the stronger the atom's ability to attract electrons.
2. **Periodic Trends**:
- Electronegativity generally increases as you move from left to right across a period and decreases as you move down a group in the periodic table.
- This is because, as you move across a period, the number of protons increases, which increases the positive charge of the nucleus, thereby attracting the shared electrons more strongly.
3. **Identifying the Relevant Period and Group**:
- The question specifies looking for the element with the highest electronegativity in a certain period and group.
- We will analyze Period 2 and Group 17 (the halogens).
4. **Elements in Period 2 and Group 17**:
- In Period 2, the elements are: Lithium (Li), Beryllium (Be), Boron (B), Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), and Neon (Ne).
- In Group 17, the elements include: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At).
5. **Comparing Electronegativity**:
- Among the elements in Period 2, Fluorine is the most electronegative element. It has an electronegativity value of approximately 4.0 on the Pauling scale.
- Neon is a noble gas and does not typically form bonds, so it does not have a defined electronegativity.
- Chlorine, while in Group 17, is in Period 3 and has a lower electronegativity than Fluorine.
6. **Conclusion**:
- Therefore, the element with the highest electronegativity belongs to Period 2 and Group 17, which is **Fluorine (F)**.
### Final Answer:
The element with the highest electronegativity is **Fluorine (F)**, which belongs to Period 2 and Group 17.
