How can we apply what we have learned?

Core electrons

Inner electrons tightly held to the nucleus, do not participate in bonding.

Valence electrons

Outer shell electrons less tightly held, participate in bonding and chemistry.

Photoelectric effect

Energy of emitted electrons depends on electronic shells, used in analytical chemistry.

Photoemission spectroscopy

Analyzes energy of ejected electrons, surface analysis technique, non-destructive.

X-ray Photoelectron Spectroscopy (XPS)

Probes core electrons for analysis.

Ultraviolet Photoelectron Spectroscopy (UPS)

Probes valence electrons and chemical bonding.

Atomic and emission spectra

Used in AAS applications for quality control and forensic science.

Covalent bonding

Formed by shared electrons between atoms, short-range and directional.

Hydrogen

Forms molecular orbitals, can interact in-phase or out-of-phase, important in biological chemistry.