Electrons in Atoms and the Periodic Table

These flashcards cover essential vocabulary related to electrons, atomic structure, and periodic trends as discussed in the lecture.

Inert Gas

A gas that does not undergo chemical reactions under a set of given conditions; helium is an example.

Reactivity

The tendency of a substance to engage in chemical reactions; hydrogen is known for its high reactivity.

Bohr Model

An early model of the atom where electrons travel in fixed orbits around the nucleus.

Quantum-Mechanical Model

A modern model of the atom that describes electrons in terms of probabilities rather than fixed orbits.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in chemical bonding.

Electron Configuration

The distribution of electrons in an atom's orbitals, showing which orbitals are occupied.

Photons

Particles of light that carry energy and exhibit both wave-like and particle-like properties.

Ionization Energy

The energy required to remove an electron from an atom in the gas phase.

Periodic Law

When elements are arranged by increasing atomic number, properties recur periodically.

Noble Gases

Group of inert gases, including helium and neon, known for their lack of reactivity.