Electronegativity, Periodic Trends & Green Technology

What Is Electronegativity?

Electronegativity is an atom's ability to attract shared electrons in a chemical bond.

In simpler terms, it measures how strongly an atom pulls bonding electrons toward itself.

• High electronegativity = Strong attraction to shared electrons.

• Low electronegativity = Weak attraction to shared electrons.

Across a period (left to right): Electronegativity generally increases.

Why?

1. The number of protons increases.

2. Effective nuclear charge generally increases.

3. The nucleus attracts shared bonding electrons more strongly.

4. Electronegativity increases.

Down a group: Electronegativity generally decreases.

Fluorine has the highest electronegativity on the Pauling scale because it strongly attracts shared electrons.

Electronegativity concerns electrons shared in a chemical bond.

Ionization energy concerns removing an electron.

Electron affinity concerns an atom gaining an electron.

Applying Periodic Properties to Green Technology

• Silicon in Solar Cells

1. Silicon is a semiconductor.

2. It has four valence electrons that allow it to form a stable crystal structure.

3. Sunlight provides energy that allows electrons to move into conducting states.

4. This movement of electrons helps generate electrical energy.

• Lithium in Rechargeable Batteries

1. Lithium has one valence electron.

2. It readily forms positive lithium ions (Li⁺).

3. Lithium ions can move between the battery's electrodes during charging and discharging.

4. This movement allows the battery to store and release electrical energy.