Chapter 3 - Atoms, Electrons, and Periodic Table

Ernest Rutherford

________: discovered that the atom is mainly made up of empty space but has a concentrated positive charge in the center.

Joseph John Thomson

________: discovered the existence of a negatively charged particle (known today as an electron)

Pauli exclusion principle

________: only two electrons of opposite spin could occupy an orbital.

Emission spectra

________: when atoms in an excited state emit photons when they fall to lower energy levels.

Orbitals

________: wave functions that give information about an electrons energy and location within an atom.

Absorption spectrum

________: results when atoms absorb photons of certain wavelengths and are excited from lower to higher energy levels Chapter 3.2: The Quantum Mechanical Model of the Atom.

Aufbau principle

________: build up the ground state electronic structure for each atom.

Ground state

________: electron- density probabilities for the lowest energy level.

Arrow up/down

________ : orbital with an electron that spins in that direction.

Niels Bohr

________: developed a similar atomic model to Rutherford but helped explained that electrons had certain restrictions:

Uncertainty principle

________: impossible to know the position and momentum of an object beyond a certain measure of precision.

Dmitri Mendeleevs periodic table

________: listed known elements increasing atomic mass.

Hunds rule

________: no two electrons can have the same set of quantum numbers.

Planck

________ suggested that matter, at the atomic level, can absorb or emit only discrete quantities of energy; Quantum of energy: these specific quantities.

Electron affinity

________: change in energy that occurs when a(n) ________ is added to a gaseous atom.

Quantum mechanical model of the atom

________ : a model of the atom that described atoms as having wave- like properties.

Atomic period

as you go across decrease in atomic size results in effective nuclear charge increasing.

Down group

inner electrons increase which increases shielding effect.

Nuclear model

________: diagram of an atom that pictures electrons in motion around the atomic nucleus.

Empty box

________: orbital with no electrons.

Ionization energy

________: the energy needed to remove one electron from ground state gaseous atom.

John Daltons atomic theory

________: atoms are tiny, solid, and indestructible spheres.

Orbital diagram

________: uses a box for each orbital in each given principal energy level.

Discovery of neutron help

The ________ explain why the atomic nucleus did not fly apart or what the total mass of an atom was.

Atomic radius

________: measurable property between nuclei of bonded.

Electron configuration

________: shorthand notation of number and arrangement of electrons.