atomic structure Flashcards
what is the quantum concept? what example do we use to model this?
-energy is present in small, discrete bundles
-a tennis ball that rolls down a staircase loses energy in small bundles- the loss is quantized
what does the Bohr model state about electrons?
an electron can have only certain energy values, called energy levels, that are quantized
what is the equation for the energy in an electron in a hydrogen atom? What does each of the variables stand for
- (-R(sub)H/n^2)
-R(sub)H= 2.179 x 10^-18 J
-n= principle quantum number
what is absorption?
electron gains energy to move to a higher energy level
what is emission?
electron loses energy to move to a lower energy level
what is the equation for an energy change for a hydrogen electron?
-R(sub)H((nf^-2)-(ni^-2))
what is an energy level?
an allowed state that an electron can occupy in an atom
what is a ground state?
lowest energy level available to an electron in an atom (when n=1)
what is an excited state?
an energy state above the grounded state
what is an electron transition?
movement of an electron between energy levels
what are some strengths of the Bohr model (2)?
-accurately predicts energy needed to remove an electron from an atom (ionization)
-allowed scientists to begin using quantum theory to explain matter at the atomic level
what are some limitations of the Bohr model (2)?
-does not account for spectra of multi-electron atoms
-movement of electrons in atoms is less clearly defined than Bohr allowed
what did Werner Heisenberg discover?
-it is impossible to know with absolute certainty both the position, x, and the momentum, p, of a particle such as an electron
-because we can’t know both of these numbers, we describe the location of electrons in terms of probability
what are orbitals? how are they described?
-3-dimensional volumes that have a high probability of finding an electron
-with 4 quantum numbers
what is the principal quantum number? what variable is it represented by? what values can it have?
-number which the energy of an electron in an atom primarily depends
-n
-any positive value
what does it mean if orbitals are in the same shell?
they have the same value for n
what is the angular momentum number? what variable is it represented by? what values can it have?
-distinguishes orbitals of a given n(shell) having different shapes
-l
- 0 to (n-1)
what l value is represented by the s orbital?
0
what l value is represented by the p orbital?
1
what l value is represented by the d orbital?
2
what l value is represented by the f orbital?
3
what is the magnetic quantum number? what variable is it represented by? what vales can it have?
-distinguishes orbitals of a given n and l; a given energy and shape but having different orientations
-m(sub)l
- any value -l…0…+l
what is the spin quantum number? what variable is it represented by? what values can it have?
-the two possible orientations of the spin axis of an electron
-m(sub)s
- -1/2 or +1/2
if n=1 and l=0, what are the possible values of m(sub)l? what is the subshell notation?
how many orbitals are in the subshell?
-0
-1s
-1