Chem H New Atomic Model

electromagnetic radiation

energy in the form of waves

wavelength

the distance between corresponding points on adjacent waves (distance from crest to crest)

frequency

the number of waves that pass a given point in a specific time (usually a second)

photon

a bundle or particle of light energy

quantum

a specific amount of bundled energy — usually carried by a photon

frequency of electromagnetic radiation & wavelength relationship

• inversely proportional

• as the wavelength of the electromagnetic radiation increases, its frequency decreases

modern quantum theory

light behaves both like waves and like particles

non-ionizing radiation

a type of low-energy electromagnetic radiation that doesn’t have enough energy to remove electrons from atoms or molecules

forms of non-ionizing radiation

uv, visibile, infrared, microwaves, radiowaves

ionizing radiation

a type of energy released by atoms in the form of electromagnetic waves or particles that has enough energy to break electrons away from the atom

sources of ionizing radiation

soil, water, vegetation, x-rays, medical devices

spectral lines

each element’s electrons give off certain frequencies of light

continuous spectra

all frequencies/wavelengths of light

photoelectric effect

phenomenon in which electrically charged particles are released from or within a material when it absorbs a specific amount of electromagnetic radiation

ground state

the lowest energy state of an atom (when electrons are in the lowest available energy level)

excited state

when an atom has a higher potential energy than its ground state (electrons are in higher energy levels than the ground state)

Einstein

observed the photoelectric effect

8

maximum number of electrons that can occupy the outermost energy level of an atom (except for H and He for which the maximum is 2)

octet

8 electrons in the outer energy level, extremely stable (noble gases)

sublevel s

• 1 orbital

• 2 electrons max

• lowest energy level found: 1st

sublevel p

• 3 orbitals

• 6 electrons max

• lowest energy level found: 2nd

sublevel d

• 5 orbitals

• 10 electrons max

• lowest energy level found: 3rd

sublevel f

• 7 orbitals

• 14 electrons max

• lowest energy level found: 4th

Hund’s rule

• empty bus seat rule

• an electron will enter an empty orbital in an energy sublevel before entering an orbital that is already occupied by another electron

Pauli Exclusion Principle

no more than two electrons can occupy a space orbital, and these two electrons must have opposite spins

Heisenberg Uncertainty Principle

it is impossible to simultaneously determine the position and energy (or velocity) of an electron

Aufbau Principle

electrons fill orbitals in order from lowest energy orbitals to highest energy orbitals

DeBroglie

discovered that electrons, moving around the nucleus, can act as both a wave and particle