Chapter 2 & 3 Flashcards
accuracy
refers to how close the measured value is to the actual value
precision
refers to how close a series of measurements are to one another
random error
error that has an equal probability of being high or low
systematic error
error that tends toward being either too high or too low
density
the ratio of a substanceโs mass to its volume
intensive property
independent of the amount of substance
extensive property
depends on the amount of substance
energy
the capacity to do work
work
the action of a force through a distance
kinetic energy
energy of motion
potential energy
energy associated with position
thermal energy
energy associated with the temperature of an object
law of conservation of energy
energy cannot be created nor destroyed
calorie
the amount of energy required to raise the temperature of 1g of water by 1 degree celsius
exothermic
system loses energy, change in energy is negative
endothermic
system gains energy, change in energy is positive
mole
amount of material containing 6.022 x 10^23 particles
Schrodinger
introduced the idea that quantum strangeness could not be transferred to the macroscopic world
quantum-mechanical model
a model that explains the strange behavior of electrons
wave-particle duality
light behaves as both particles and waves
electromagnetic radiation
a type of energy embodied in oscillating perpendicular electric and magnetic fields
amplitude
vertical height of a crest of a wave
wavelength
distance between adjacent crests of a wave
frequency
the number of cycles that pass through a stationary point in a given amount of time
wave equation
c = ๐ผ๐
electromagnetic spectrum
includes all wavelengths of electromagnetic radiation
electromagnetic radiation with the shortest wavelength
gamma rays
The most energetic forms of electromagnetic radiation have what kind of wavelength?
short wavelength
The most energetic forms of electromagnetic radiation have what kind of frequency?
high frequency
Electromagnetic Spectrum from low energy to high
Radio, Microwave, Infrared, Visible, UV, X-rays, Gamma
electromagnetic radiation with the longest wavelength
radio
interference
waves interact with each other in a characteristic way
constructive interference
waves in phase, add together, greater intensity
destructive interference
waves out of phase, subtract, cancel out
diffraction
when a wave encounters an obstacle or a slit that is comparable in size to its wavelength, it bends around it
photoelectric effect
the observation that metals emit electrons when light shines upon them
binding energy
the energy with which an electron is bound to the metal
threshold frequency
no electrons are emitted below this frequency of light
Does intensity of the light affect the threshold frequency?
no nigga
Einstein proposed:
light energy must come in packets
equation for energy of one photon
E = h๐ or E = hc/๐
Increasing the intensity of the light shown on a metal does what?
increases the amount of photons, not the energy of each photon
Threshold frequency condition
h๐ = ษธ
Equation for the Kinetic Energy of the emitted electron:
KE = h๐ - ษธ
emission spectrum
a series of bright lines. it is always the same for a particular element.
Johannes Rydberg
analyzed atomic spectra and developed an equation that predicts the wavelengths of the hydrogen emission spectrum
The Bohr Model
developed by Niels Bohr in an attempt to explain the atomic spectra. Electrons orbit nucleus in various energy states.
absorbtion spectrum
consists of dark lines on a bright background. measure by passing white light through a sample and observing what wavelengths are missing
Louis de Broglie
proposed the wave nature of the electron
de Broglie wavelength equation:
๐ = h/(mv)
The uncertainty principle
formulated by Heisenberg. states that it is not possible to know the position and velocity of an electron simultaneously.
deterministic
the present determines the future
