Chapter 2: atomic structure

Dalton

Billard ball model

Thomson

plum pudding model

discovered electrons

experience of deflection of cathode rays by magnetic field

Rutherford

model named after the guy

heavy nucleus, most mass centered in the nucleus

discovered the scattering of alpha particles by heavy atoms

Bohr

electrons in few, discreet orbits around the nucleus (kind of like planets but modified)

model leading to accurate calculation of the wavelength of light emitted by hydrogen

l values based on orbitals

s orbital = 0

p orbital =1

d orbital = 2

f orbital =3

etc.

ml

values for __ go from -l to +l

angular nodes

#of __ = l

radial

number of __ nodes = n-l-1

total number of nodes

n-1

cannot

s orbitals __have angular nodes, however, p,d,f etc. orbitals can have them, you just can’t see it without cutting them open.

n

the number of radial nodes depends on the angular momentum l, aka the type of orbital, but also on __

Dmitri Mendeleev

established periodic law and organization of elements

1869

proipertiesofelementrs reur at regular intervals

Julius Lothar Meyer

Independently contributed to the organization of the elements

ordered in order of atomic weight and grouped based on similar properties

before

the elements were organized in a table ___ the electrons were discovered by Thomson

light

electromagnetic energy

white __ can be separated into component colors based on wavelengths distribution`

decreases

E = hc/lamba

As the wavelength increases, the frequency and energy ___, and vice versa.

atomic line spectra

unique spectral signature corresponding to a specific energy emitted from an excited atom

yellow

Na+ ions emit a ___ light, specific to sodium.

Balmer series

Lines of the H atom spectrum in the visible range

1,2,3

When calculating spectral lines, the Lyman series starts at n=__, Balmer series start at n=___ and the Paschen series starts at n=__

When calculating, nl is considered the starting point of the series, but it is not the start of the entire spectra, so nh will be nl+# of the line you wish to calculate.

Rydberg

__ generalized Balmer equation which made predicting new atomic lines possible

The Rh constant named after him.

Paschen

series for H lines in the IR range

Paschen

series for H lines in UV

before

Elements were organized following the periodic law, and spectral lines discoveries happened __ the discovery of electrons by Thomson

Thomson

discovered the electrons

played with cathode rays to prove that the electrons have a negative charge

plum pudding model

Millikan

measured the electron its charge and figured out its mass of 9.11×10^-31 kg

oil droplets and X-rays experiements

Rutherford

established the nuclear model of the atom: a very small, heavy nucleus surrounded by mostly empty space

reflection of alpha particles on foil

discovered protons and neutrons aka heavy nucleus

1911

Bohr

propose an atomic model where the electrons can only exist in discrete orbits

electrons jump from one orbital to the next& each jump correspond to a specific amount of energy

discrete stationary states called orbital

QUANTIZED energy levels

limitations of the Bohr atom

• only works for 1 electron system like the H atoms

• electron is treated as a particle “in orbit” around the nucleus

• orbit is always circular (true for s orbitals, not the other types)

De Broglie

electrons are discrete bits of matter (particles) which also have wave-like properties with wavelength and frequency

Einstein

light is an electromagnetic wave and a localized pack of discrete energy (particle-like)

photoelectric effect

Heisenberg uncertainty principle

we never know where the electron is located exactly, always uncertainty about that