Chapter 3 - Atoms, Electrons, and Periodic Table

Joseph John Thomson

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

Ernest Rutherford

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

Emission spectra

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

occupy orbitals

Electrons do not actually ________, instead, calculate probability densities for electrons.

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.

Electron

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

higher energy

Absorption spectrum: results when atoms absorb photons of certain wavelengths and are excited from lower to ________ levels**

atomic size

Across period: as you go across decrease in ________ results in effective nuclear charge increasing.

Discovery of neutron help

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

specific energy

Atom has only ________ levels, called stationary states.

Ionization energy

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