CHEM 111 Chapter Notes - Chapter 11: Prestressed Concrete, Vsepr Theory, Valence Electron

• School: Drexel University
• Department: Chemistry
• Course: CHEM 111
• Professor: Wambsgans Anthony

Document Summary

Ionizaion energy- the energy required to remove an electron from an atom, an ion, or a molecule. For each astep down a group, an addiional energy level is added to the atom. The average distance from the nucleus to the outside edge of the atom must increases as each new energy level is added. The atoms get bigger as electrons are placed in these new higher energy levels: decreases across a row. As we move from let to right across a period, electrons within the same block are being added to the same principal energy level. Within a given energy level, we expect the orbitals to have the same size. But each ime an electron is added, a proton is added to the nucleus as well. The increase in posiive charge (in the nucleus) pulls the electrons closer to the nucleus, which results in a gradual decrease in atomic radius across a period.