Kaplan MCAT General Chemistry Review: Chapter 1.3 - Key Concepts of Rutherford, Planck, and Bohr

Ernest Rutherford

in 1910, ___________ provided experimental evidence that an atom has a dense, positively charge nucleus that accounts for only a small portion of the atom's volume

Max Planck

____________ developed the first quantum theory, proposing that energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta

quanta

Planck proposed that energy emitted from electromagnetic radiation from matter comes in discrete bundles called...

E=hf (energy= Planck's constant x frequency of radiation)

the energy of a quantum is vein by the Planck reaction:

6.626 x 10^-34 joules per second

Planck's constant (h)=

L = nh/2pi (n=principal quantum number, h=planck's constant)

Bohr predicted that the possible values fro the angular momentum of an electron orbiting a hydrogen nucleus could be given by:

Bohr

in the _______ model of the atom, a dense, positively charged nucleus is surrounded by electrons revolving around the nucleus in orbits with distinct energy levels

E=-RH/n^2

Bohr related the permitted angular momentum values to the energy of the electron to obtain:

principal quantum number (n)

Energy (E) is directly proportional to the....

increases

the energy of an electron increases/decreases the farther out from the nucleus that it is located

ground state

the __________ of an atom is the state of lowest energy in which all electrons are in the lowest possible orbitals

excited state

an atom is in a ______________ when at least one electron has moved to a sub shell of higher than normal energy

ground state

at room temperature, the majority of atoms in a sample are in the...

photons (light)

because a lifetime of an excited state is brief, the electrons will return rapidly to the ground state, resulting in the emission of describe amounts of energy in the form of...

E= hc/λ (h is planck's constant, c is the speed of light 3 x 10^8, lambda is wavelength)

the electromagnetic energy of the photons released from the return to ground state can be determined using the equation:

AHED (absorb light, higher potential, excited, distant from the nucleus)

as electrons go from a lower energy level to a higher energy level, they get...

atomic emission spectrum

because each element can have its electrons excited to a different set of distinct energy levels, each possesses a unique _______________ which can be used as a fingerprint for the element

Lyman series

the group of hydrogen emission lines corresponding to transitions from energy levels n≥2 to n=1 is known as the...

Balmer series

the group of hydrogen emission lines corresponding to transitions from energy levels n≥3 to n=2 is known as the ___________ and includes four wavelengths in the visible region

Paschen series

the group of hydrogen emission lines corresponding to transitions from n≥4 to n=3

E=(hc)/λ=Rh{[1/ni^2]-[1/nf^2]}

the energy associated with a change in the principal quantum number from a higher initial value to a lower final value is equal to the energy of the photon predicted by Planck's quantum theory, so we can derive this equation:

absorption spectrum

in addition to a unique emission spectrum, every element possesses a characteristic...

Rydberg unit of energy, 2.18 x 10^-18 J/electron

Rh=

wavelength

Energy is inversely proportional to...

difference in energy between the higher-energy initial state and the lower-energy final state

the energy of the emitted photon corresponds to the...