Unit 2: Quantum and Periodic Table Flashcards
Quantum
How matter and energy interact
Niels Bohr
Used the research and discovery of pervious scientists to come up with a system consisting of a small, dense nuclear surrounded by orbiting electrons
Bohr’s Planetary Model of the Atom
Electrons travel in definite energy levels without radiating energy, electrons in each orbit have a certain amount of energy, energy increase as distance from the nucleus increases, electrons will lose energy
Planetary Model (Bohr Model)
Electrons can gain energy when heated, electrons gain this energy in small specific amounts called quanta, electrons are said to be excited after it gains a quanta of energy
Quanta
The small specific amounts of energy gained by electrons
Ground State
The lowest energy state of an atom
Excited State
A state in which an atom has a highest potential energy than it has in its ground state
Quantum
The minimum quantity of energy that can be lost or gained by an atom
Photon
A particle of electromagnetic radiation having zero rest mass and carrying a quantum of energy
Emissions Spectrum
The range of wavelengths emitted by an atom or compound stimulated by either heat or electric current (excited state)
Absorption Spectrum
The range of wavelengths absorbed by an atom or compound (the sample is not stimulated) (ground state)
Atomic Emissions Spectrum
The set of frequencies of the electromagnetic spectrum emitted by the excited electrons of an atom, will produce only a few lines of specific colored light, produced by hot gases giving off energy in the form of photons
Inadequacy of the Bohr Model
The bohr model explained the energy absorbed and emitted by the hydrogen atom which contains one electron; but it failed to explain more complex atoms
Quantum Theory
Describes mathematically the wave properties of electrons and other very small particles, was proposed by Max Planck
Planck’s Constant
States that atoms can only gain or lose electrons in certain amounts, this is the least amount of energy that can gained or lost by an atom, there is no inbetween, energy gain or loss is incremental, planck’s constant is 6.626x10^-34 J
Electromagnetic Radiation
A form of energy that exhibits wavelike behavior as it travels through space, all the forms of electromagnetic radiation come together to form the electromagnetic spectrum
Velocity
The speed in a given direction
Wavelength
The distance between two waves
Frequency
The number of waves during a period of time
Amplitude
The height of a wave
Speed of light
c= 3.00x10^8 m/s
Wave properties of electromagnetic radiation
Waves with low energy have low frequency and a big wavelength, waves with high energy have a high frequency and a small wavelength
Wavelength and Frequency (relationship)
inverse relationship
Energy and Frequency (relationship)
direct relationship
Wavelength and Energy (relationship)
Inverse relationship
Photoelectric Effect
A phenomenon where electrons are emitted from the metal surface when the light of sufficient frequency is found, Albert Einstein suggested this idea, used planck’s idea that a light is a particle (photon)
De Broglie’s Hypothesis
All matter exhibits wave-like properties and relates the observed wavelength of matter to its momentum, so the wave particle duality
Wave Particle Duality
The concept in which quantum entities exhibit particle or wave properties according to experimental circumstances
Heisenberg Uncertainty Principle
It is impossible to determine both the position and velocity of an electron or any other particle at the same instance, helped to develop the modern quantum theory, we cannot be certain where electrons are at any given moment
Schrodinger’s Wave Equation
Predicts analytically and precisely the probability of events or outcome of a wave based on the energy and momentum of an electron