Chapter 2 - The Quantum Mechanical Model of the Atom Flashcards
How do electrons behave?
much differently than large objects (classical physics does not describe electrons)
What is Quantum Mechanics?
physics of the really small, forms the basis of our understanding of mater and its behaviour at the subatomic level
What is light?
A form of electromagnetic radiation
Composed of perpendicular oscillating waves, one for the electric field and one for the magnetic field
In what way does light move?
At a constant speed. notified by ‘c’ (speed of light) = 3.00x10^8 m/s
What is Amplitude?
vertical height of a crest or depth of a trough
determines the lights intensity/ brightness
greater amplitude = greater intensity
What is Wavelength?
distance between 2 adjacent crests or troughs etc. is measured in units like metres, micrometres and nanometres
What is frequency?
the number of waves that pass a point in a given period of time
units are cycles per second (s^-1) or hertz (Hz)
1s^-1 = 1Hz
What is the relationship between wavelength and frequency?
they are inversely proportional
What is the equation for Frequency?
Frequency (s^-1) = Speed of light (3.00x10^8) / wavelength (m)
What is total energy (light as a wave)?
proportional to the amplitude of the waves and their frequency
The larger the amplitude, the more force it has
The more frequently the waves strike, the more total force there is.
On the electromagnetic spectrum what does a shorter wavelength mean?
(high frequency) light has higher energy
Which wave of light has the lowest energy?
Radio-wave light
Which wave of light has the highest energy?
Gamma-ray light
What are some examples if high-energy electromagnetic radiation and what could they do to molecules?
UV, X-ray, Gamma can potentially damage biological molecules
What is the wavelength of Gamma rays?
10^-15 m
What is the wavelength of radio waves?
10^5 m
list the different types of wavelength from low to high energy
Radio, Microwave, Infrared, Visible , Ultraviolet, X-Ray, Gamma Ray
What is the region for visible light?
between 400nm - 750nm (small)
What is Interference (waves)?
the interaction between multiple waves
What is constructive interference?
waves that are in phase and add to make a larger wave
What is destructive interference?
waves that are out of phase and cancel each other out
What is diffraction?
When propagating waves encounter an opening in a barrier and bend around it. (travelling particles do not diffract)
What does the diffraction of waves through 2 slits result in?
an interference pattern (alternating regions of constructive and destructive interference) (waves out of phase = dark spot & vice versa)
What is the photoelectric effect?
that when light hits a metal surface, electrons can be ejected