unit 7 Flashcards
electromagnetic radiation
light
Planck’s constant
allows us to relate energy and frequency; represented by “h”
rods & cones
colles in the eye which detect light
spectrometer
scientific instrument that can analyze the light in a star and determine all of the individual wavelengths that make it up-determining its elemental composition. Method known as spectroscopy. Can also be applied to chemicals
quantum assumption
electrons can jump orbit but can not be anywhere in between
excited
when an electron moves from an orbit close to the nucleus to an orbit far away from the nucleus – opposite “de-excited”
wavelength
the distance between the crests or troughs of a wave
amplitude
a measure of the height of the crests or the depths of the troughs of a wave
physical constant
a measurable quantity in nature that does not change
frequency
the number of wave crests or troughs that pass a given point each second
When wavelength is — frequency is small
large
When wavelength is small frequency is
large
as a light waves frequency increases, its energy
increases
As a light waves wavelength increases its energy
decreases
crookes tube
glass tube with a tiny amount of gas, hooked up to a battery, resulting in a faint yellow-grebe glow on the end of the tube. sometimes referred to as a cathode ray tube
Every substance on earth has
electrical charges
electron
negative element of atom that has common ration of charge to mass
proton
positively charged
nutron
neutral
Atomic number
to number on each box in the periodic table; tells how many protons
all atoms have equal numbers of
electrons and protons
isotopes
Atoms with the same number of protons but different numbers of neutrons
isotopes behave identically in their chemistry; the main difference between them is
their mass
Mass number
the total number of neutrons and protons in an atom
isotopic enrichment
the process of artificially increasing the amount of 235U in the Uranium (when making a nuclear bomb)
Rutherford model
planetary model
particle/wave duality theory
the theory that light sometimes behaves as a particle and sometimes as a wave
quantum mechanical model
says that, in addition to the bohr model, electrons need energy to go into orbits that are far away from the nucleus and need to release energy in the form of light in order to get back to orbits close to the nucleus
orbitals
the ‘clouds’ in which electrons orbit, according to the quantum mechanical model
s orbital
simplest type of orbital; spherically shaped
p orbital
dumbbell-shaped orbital with nucleus in the center; no first energy level/1p; for each energy level there are 3 different orientations in space
All forms of matter try to
stay in their lowest possible energy state
ground state
lowest possible energy state for a given substance
