Atom Test Flashcards
Democritus
atomos
first to identify the possibility of an atom
smallest piece of matter
Atomos
individible
John Dalton
father of modern atomic theory
5 parts to the theoy
Parts to Dalton’s atomic theory
elements are composed of atoms
element’s atoms are identical in mass
Ernest Rutherford
gold foil experiment
predicted existence of neutrons
What does the gold foil experiment tell us?
atom has small positive nucleus
remainder is empty space
James Chadwick
helped with the development of the nuclear model
discovered the neutron
Neils Bohr
planetary model of the atom
electrons travel in specified energy levels
spectral lines produced when electrons move
Atomic number
is the number of protons
Mass number
mass of the entire nucleus (protons and neutrons)
Which two particles have a similar mass?
protons and neutrons
Ions
an atom that gained or lost electrons
What are ions trying to become?
trying to become stable at 8 valence electrons
Cation
is formed when an atom looses 1 or more electrons
positive charge
Anion
a neutral atom gains one or more electrons
negative charge
Isotopes
atoms of the same elements with different mass numbers
Wavelength
the distance between any two points in a wave
Frequency
the number of cycles that pass through a point in a unit of time
Unit of wavelength
nanometers or meters
if given in nm use (1*10^-9)
Unit of frequency
sec^-1 or Hertz
Relationship between wavelength and frequency
indirectly proportional
as one increases the other decreases
What has the shortest wavelength of the visible spectrum?
Violet
What has the longest wavelength of the visible spectrun?
Red
What has the lowest frequency of the visible spectrum?
Red
What has the highest frequency of the visible spectrum?
Violet
What has the longest wavelength (general)
Radio waves
What has the shortest wavelength (general)
Gamma rays
What has the highest frequency (general)
Gamma rays
What has the lowest frequency (general)
radio waves
Which waves have the most energy?
Gamma rays
Max Planck’s theroy
Founder of quantum theory
light and electromagnetic waves were emitted in packets of energy called quanta
Photoelectric effect
the production of electrons when a light is shown on a material
light can be used to push electrons out of a solid surface
Heisenburg Uncertainity
states that the position and velocity of an object can not be measured together
Valence electrons
the number of electrons in the outmost energy level
these are the electrons that are involved in chemical reactions
Subatomic particles
protons, electrons, and neutrons
Average atomic mass
the weighted average of the atomic masses of the naturally occurring isotopes of an element
Major regions of the electromagnetic spectrum in order of increasing wavelength
Gamma rays x-rays ultra-violet visible infrared microwaves TV radio
The cathode ray experiement
JJ Thompson
Discovered the electron
the electrons were attracted to the positive side
First model to include electrons
plum pudding model
Shrodinger
formulated an equation from which the probability of finding an electron at that location
Atomic orbital
specifies a volume of space that the electron is most likely to be found
Aufbau principle
electrons occupy the orbital of the lowest energy first
Electromagnetic waves
progressive, repeating disturbances that come from the movement of electric charges
Max Planck’s other idea
light has particle properties called Photons
E=hv
Hund’s rule
electrons occupy oribitals of the same energy in a way that makes the number of electrons with the same spin as large as possible
