Orbitals Flashcards
does all light travel at the same velocity?
yes
speed of light units
c
3.00E8 ms-1
what is radiation measured in?
wavelength in meters and frequency in Hz or s-1
relationship between frequency and wavelength
wavelength x frequency = c
define amplitude
intensity of radiation, measure of strength of light
higher the frequency
the smaller the wavelength
what are quanta?
packets that energy come in
- the minimum amount certain properties of a system can change
- photons (when referring to light) are particle like interpretation of light waves
equations for photons, energy and frequency
energy = planks constant x frequency
energy = (planks constant x c)/wavelength
light has properties of….
quanta and waves
what is planks constant?
6.63e-34 J
passing light through a gas and then a prism:
- spectrum of colour with dark lines
- absorbing light at specific wavelengths causing darkness
excited gas emitting light:
- coloured lines at specific wavelengths
- emitting light
absorption
electron absorbs energy and moves to a higher energy level
emmission
electron loses energy releasing energy as light
why does each element have a unique spectrum?
due to electrons
the value of each energy level for hydrogen (J)
energy of level = - (-2.18e-18 J)/energy level squared
what does energy do as an electron becomes more stable?
lowers
Rydberg equation
determines difference in energy as wavelengths between two shells
1/wavelength = 1.097e7 (1/n^2 - 1/n^2)
first energy level is the smaller one
wave-particle duality
sometimes electrons act as particles and sometimes like waves
so matter should exhibit wavelength properties
only really light things like electrons have detectable wavelength
- double slit experiment
what is the schrodinger equation for?
to make a statement about the probability of locating the electron based on the x,y and z axes - probability density
what are quantum numbers?
represent unique solutions to the schrodinger equation. there are 4 and each electron in an atom has a unique set
principle quantum number (n)
location of energy level eg n=4
angular momentum quantum number (l)
shape of the orbital. ranges from 0 to n-1.
orbital
an area where an electron is likely to be 95% of the time
magnetic quantum number (ml)
orientation of an atomic orbital around the nucleus. takes values between -l to l. total number of orbitals with a value of 1 is 2l + 1
spin quantum number (ms)
the direction of the spin of an electron in an orbital. -1/2 or 1/2. only two directions each orbital is occupied by two electrons.
radial density function
- probability of finding an electron in a 3D spherical shell
- distance r from the nucleus
- volume of shells increases as r increases
- function increases and then returns to 0 again
- no space in the nucleus, volume increases so more electrons until too far from the nucleus for there to be electrons
