Modelo atómico de Bohr[editar]
Energía de las órbitas atómicas[editar]
![{\displaystyle \ E=E_{k}+E_{p}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e64f3793a518d5c29b0e8cbc66c5f09e83d80eda)
![{\displaystyle \ E={\frac {1}{2}}mv^{2}-{\frac {e^{2}}{4\pi \epsilon _{0}r}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/fe370ecadb9731ab374ab1b19a67c1b2189883af)
![{\displaystyle \ E={\frac {r}{2}}({\frac {mv^{2}}{r}})-{\frac {e^{2}}{4\pi \epsilon _{0}r}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f949514b20de97c4fc4b8a6df79a274c831818de)
![{\displaystyle \ E={\frac {e^{2}}{8\pi \epsilon _{0}r}}-{\frac {e^{2}}{4\pi \epsilon _{0}r}}\to E=-{\frac {e^{2}}{8\pi \epsilon _{0}r}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/b18965cb6aa064942d6d0fd200e8def1049c5187)
![{\displaystyle \ L^{2}=m^{2}r^{2}v^{2}=m{\frac {mv^{2}}{r}}r^{3}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/798cb0ef2ef435656419f2eb29490786d931332e)
![{\displaystyle \ L^{2}=m({\frac {e^{2}}{4\pi \epsilon _{0}r^{2}}})r^{3}=2mr^{2}({\frac {e^{2}}{8\pi \epsilon _{0}r}})=-2mr^{2}E}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ad5f5d67d52ab6a100f9ba45e0dd411cb4bb377e)
![{\displaystyle \ L^{2}=m({\frac {e^{2}}{4\pi \epsilon _{0}}})r\to r={\frac {4\pi \epsilon _{0}}{me^{2}}}L^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/6a7ba419d15b9afb7e06eee156a66ff23a9e679a)
![{\displaystyle r={\frac {4\pi \epsilon _{0}}{me^{2}}}n^{2}\hbar ^{2}\to r=a_{0}n^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/2771f69001360020f94615f2739316e002da994d)
![{\displaystyle a_{0}={\frac {4\pi \epsilon _{0}\hbar ^{2}}{me^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/efb7ecb8ad7fbff2f47949349bc6045e2eb51cf3)
![{\displaystyle E={\frac {L^{2}}{-2mr^{2}}}={\frac {-n^{2}\hbar ^{2}}{2m}}{\frac {m^{2}e^{4}}{16\pi ^{2}\epsilon _{0}^{2}n^{4}\hbar ^{4}}}=-{\frac {me^{4}}{32\pi ^{2}\epsilon _{0}^{2}n^{2}\hbar ^{2}}}=-{\frac {me^{4}}{8\epsilon _{0}^{2}n^{2}h^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/01fb620b7035aec59b33af6aeec9380241a70578)
Series espectrales[editar]
La ley de Coulomb establece que las energía potencial electrostática de un electrón orbitando alrededor del núcleo es inversamente proporcional a su distancia de éste. Dicha energía potencial es siempre negativa (puesto que la fuerza es de atracción, no de repulsión) y se expresa mediante la siguiente fórmula:
![{\displaystyle E={\frac {e^{2}}{4\pi \epsilon _{0}r}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8ee492d18e9ad6db9bee3e2e92ff66778d2ae300)
De esta fórmula se deduce que la dislocación de un electrón hacia una órbita atómica situada a mayor distancia del núcleo (y por lo tanto, más energética), requiere de la absorción de un fotón cuya energía viene determinada por la siguiente ecuación:
![{\displaystyle \ E_{foton}=E_{f}-E_{i}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f4c9b5b49c5fec7c250c04ca85795f9e7c3ef552)
![{\displaystyle E_{foton}=-{\frac {me^{4}}{8\epsilon _{0}^{2}n_{f}^{2}h^{2}}}+{\frac {me^{4}}{8\epsilon _{0}^{2}n_{i}^{2}h^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/883f95c22f26fd442b62d3a148cf8a8e63027b97)
![{\displaystyle E_{foton}=-{\frac {me^{4}}{8\epsilon _{0}^{2}h^{2}}}[{\frac {1}{n_{i}^{2}}}-{\frac {1}{n_{f}^{2}}}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f1e3e001e9bb2bc1e242961240280897f03d8864)
![{\displaystyle E_{foton}=R[{\frac {1}{n_{i}^{2}}}-{\frac {1}{n_{f}^{2}}}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c8bc56237f10a110b4e865de429f8c6cb0321d69)
(Series de Lyman)
(Series de Balmer)
(Series de Paschen)
Modificaciones introducidas por Schrödinger[editar]
![{\displaystyle \ \nabla _{\alpha }f^{\alpha }={\frac {1}{\sqrt {g}}}{\frac {\partial ({\sqrt {g}}f^{\alpha })}{\partial x_{\alpha }}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1de9c9d3b7c65b265fd30bd001cbad4cdafde7aa)
![{\displaystyle \ \nabla _{\alpha }f^{\alpha }={\frac {1}{r^{2}\sin \theta }}{\frac {\partial (r^{2}\sin \theta f^{\alpha })}{\partial r}}+{\frac {1}{r^{2}\sin \theta }}{\frac {\partial (r^{2}\sin \theta f^{\alpha })}{\partial \theta }}+{\frac {1}{r^{2}\sin \theta }}{\frac {\partial (r^{2}\sin \theta f^{\alpha })}{\partial \phi }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d74cc9e5093a7dd60d5548281559d9f86020a513)
![{\displaystyle \nabla ={\vec {u}}_{r}{\frac {\partial }{\partial r}}+{\vec {u}}_{\theta }{\frac {1}{r}}{\frac {\partial }{\partial \theta }}+{\vec {u}}_{\phi }{\frac {1}{rsin\theta }}{\frac {\partial }{\partial \phi }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3fdac4159adaa877e2f64a9efc0b37f5c067e4a5)
Relación de De Broglie[editar]
![{\displaystyle \ h\nu =pc}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1752b624e4e5681169d8f0b40219fe5ab6c67af7)
![{\displaystyle p=h{\frac {\nu }{c}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/61c1c3f67ebe7488dfc5dfbb5a001f7274a863a2)
![{\displaystyle p=h{\frac {1}{\lambda }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e5588c0a74a7a3285ded9fe114a77e17ac4acbc3)
![{\displaystyle p=\hbar k}](https://wikimedia.org/api/rest_v1/media/math/render/svg/24fee69175538303b28ac54e907baf53d0a58dbf)
Principio de incertidumbre de Heisenberg[editar]
Principio de incertidumbre generalizado[editar]
Referido a la posición y el momentum[editar]
Solución de la ecuación de Schrödinger en coordenadas esféricas[editar]
![{\displaystyle {\frac {\hbar ^{2}}{2m}}\nabla ^{2}\psi +V\psi =E\psi }](https://wikimedia.org/api/rest_v1/media/math/render/svg/bb3db492ddefd19a2865a58747beb3588d41f52e)
![{\displaystyle {\frac {\hbar ^{2}}{2m}}[{\frac {1}{r^{2}}}{\frac {\partial }{\partial r}}(r^{2}{\frac {\partial }{\partial r}})+{\frac {1}{r^{2}sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial }{\partial \theta }})+{\frac {1}{r^{2}sin^{2}\theta }}{\frac {\partial ^{2}}{\partial \phi }}]\psi +V\psi =E\psi }](https://wikimedia.org/api/rest_v1/media/math/render/svg/a08e3e2f9919f6d9f49f4f8175a42530d2aecfaf)
Separación de variables[editar]
![{\displaystyle \,\psi _{nlm}(r,\theta ,\phi )=R(r)Y(\theta ,\phi )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/df767dc96b64e5bc5aaf9797a1ed6e7b65b77aca)
Reformulamos la ecuación de acuerdo con los nuevos parámetros:
![{\displaystyle {\frac {\hbar ^{2}}{2m}}[{\frac {Y}{r^{2}}}{\frac {\partial }{\partial r}}(r^{2}{\frac {\partial R}{\partial r}})+{\frac {R}{r^{2}sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial Y}{\partial \theta }})+{\frac {R}{r^{2}sin^{2}\theta }}{\frac {\partial ^{2}Y}{\partial \phi }}]+VRY=ERY}](https://wikimedia.org/api/rest_v1/media/math/render/svg/bd231e23fa1e2bc0376feda1ba9df2702c8c6b1c)
Dividimos ahora entre RY y multiplicamos por
, obteniendo:
![{\displaystyle {\frac {1}{R}}{\frac {\partial }{\partial r}}({\frac {\partial R}{\partial r}})+{\frac {1}{Y}}[{\frac {1}{sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial Y}{\partial \theta }})+{\frac {1}{sin^{2}\theta }}{\frac {\partial ^{2}Y}{\partial \phi }}]+{\frac {2mr^{2}}{\hbar ^{2}}}V={\frac {2mr^{2}}{\hbar ^{2}}}E}](https://wikimedia.org/api/rest_v1/media/math/render/svg/20d69a4cc674459c20876f683496c4d9e3b43aa7)
![{\displaystyle {\frac {1}{Y}}[{\frac {1}{sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial Y}{\partial \theta }})+{\frac {1}{sin^{2}\theta }}{\frac {\partial ^{2}Y}{\partial \phi }}]={\frac {2mr^{2}}{\hbar ^{2}}}(E-V)-{\frac {1}{R}}{\frac {\partial }{\partial r}}(r^{2}{\frac {\partial R}{\partial r}})}](https://wikimedia.org/api/rest_v1/media/math/render/svg/9153aa95a4b2b9d8a433b492c99cc5b3a30b1b2e)
El miembro izquierdo de esta ecuación es una función de las coordinadas angulares
y
, mientras que el miembro derecho lo es de la coordinada radial
. Puesto que dichas variables son independientes entre sí, hemos de deducir que el valor de los miembros de esta igualdad equivale a una constante, a la que llamaremos
:
![{\displaystyle {\frac {1}{Y}}[{\frac {1}{sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial Y}{\partial \theta }})+{\frac {1}{sin^{2}\theta }}{\frac {\partial ^{2}Y}{\partial \phi ^{2}}}]=-l(l+1)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/1127ef944680a9819c968ee4162eaf04abdb611c)
![{\displaystyle {\frac {2mr^{2}}{\hbar ^{2}}}(E-V)-{\frac {1}{R}}{\frac {1}{r^{2}}}{\frac {\partial }{\partial r}}(r^{2}{\frac {\partial R}{\partial r}})=-l(l+1)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/844bd91c419dd3340bf69bbb4fa6f30241320ee7)
La primera se denomina ecuación angular, mientras que la segunda toma el nombre de ecuación radial.
Ecuación angular[editar]
Tomemos la ecuación angular y procedamos a imponer sobre ella una nueva separación de variables. Si consideramos que la función
es un producto de las funciones
y
, la ecuación quedaría de este modo:
![{\displaystyle {\frac {1}{Y}}[{\frac {\Phi }{r^{2}sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+{\frac {\Theta }{r^{2}sin^{2}\theta }}{\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}]=-l(l+1)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f85bfe4b294c0faeee4232e0a1593c6c0687c15c)
![{\displaystyle {\frac {1}{\Theta }}{\frac {1}{r^{2}sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+{\frac {1}{\Phi }}{\frac {1}{r^{2}sin^{2}\theta }}{\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}=-l(l+1)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c39e1d56f6f95280bea078c9c2f88b41bdb92dd8)
Multiplicamos ahora por
, obteniendo con ello:
![{\displaystyle {\frac {1}{\Theta }}sin\theta {\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+{\frac {1}{\Phi }}{\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}=-l(l+1)r^{2}sin^{2}\theta }](https://wikimedia.org/api/rest_v1/media/math/render/svg/2bc18b95a5d849b145930ac5ef7a52b52fce0cba)
![{\displaystyle {\frac {1}{\Theta }}sin\theta {\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+l(l+1)r^{2}sin^{2}\theta =-{\frac {1}{\Phi }}{\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/0beb7e0ccb0beb8f0465ffc993437bdec9937b4d)
Puesto que el primer miembro de la ecuación es una función de
, mientras que el segundo lo es de
, hemos de deducir que el valor de ambos es una constante, a la que llamaremos
:
![{\displaystyle -{\frac {1}{\Phi }}{\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}=m^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/ad420a5b03df626f3dd9486b253d7da4d19f9b73)
![{\displaystyle {\frac {1}{\Theta }}sin\theta {\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+l(l+1)r^{2}sin^{2}\theta =m^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/68a02f7006e7dc8e69841d2dc220561cd81d64e8)
La primera de estas ecuaciones tiene una solución bastante sencilla:
![{\displaystyle {\frac {\partial ^{2}\Phi }{\partial \phi ^{2}}}=-m^{2}\Phi \to \Phi (\phi )=e^{im\phi }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/771de28b9e40d4373e6197793798eeaee4de8290)
Como
es una coordinada angular, la función
está sometida al siguiente gauge:
![{\displaystyle \ \Phi (\phi )=\Phi (\phi +2\pi )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/24f7108dcbbb3d40bcfdafe7c008714a924beed0)
![{\displaystyle \ e^{im\phi }=e^{im\phi }e^{im2\pi }\to e^{im2\pi }=1}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5384278a17858023553cb29be98d2aeb1878b171)
De lo que se deduce que m ha de ser un número entero.
La segunda de las ecuaciones, relativa a la función
, tiene una solución algo más compleja:
![{\displaystyle {\frac {1}{\Theta }}sin\theta {\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial \Theta }{\partial \theta }})+l(l+1)r^{2}sin^{2}\theta =m^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/68a02f7006e7dc8e69841d2dc220561cd81d64e8)
![{\displaystyle \Theta (\theta )=AP_{m}^{l}(cos\theta )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3e297f0add7b714325a394d319780fb1dfc5f1cf)
![{\displaystyle P_{m}^{l}(cos\theta )=(1-x^{2})^{|m|/2}({\frac {d}{dx}})^{|m|}P_{l}(x)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c70e5e69d8095ad650e2512b3c982be692290cb6)
![{\displaystyle P_{l}(x)={\frac {1}{2^{l}l!}}({\frac {d}{dx}})^{l}(x^{2}-1)^{l}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5f5012c0a89999369ee7d354d6bf17b1901f5f84)
Donde la fórmula
recibe el nombre de Función asociada de Legendre, mientras que la expresión
se denomina Polinomio de Legendre.
es una constante que se obtiene por normalización:
![{\displaystyle \int _{0}^{2\pi }\int _{0}^{\pi }Y(\theta ,\phi )d\theta d\phi =1\to \int _{0}^{2\pi }\int _{0}^{\pi }AP_{m}^{l}(cos\theta )e^{im\phi }d\theta d\phi =1\to A=}](https://wikimedia.org/api/rest_v1/media/math/render/svg/df2b9c5f9aa1ec23d9e484d681a6b951cf6a0e68)
De este modo, la función
tiene los siguientes componentes:
![{\displaystyle \ Y(\theta ,\phi )=\Theta (\theta )\Phi (\phi )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/383cb69a1d821afa973f9dddf33eae638e3ba3b1)
![{\displaystyle \ Y(\theta ,\phi )=AP_{m}^{l}(cos\theta )e^{im\phi }\to Y(\theta ,\phi )=AP_{m}^{l}(cos\theta )e^{im\phi }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d9469d41e761cc4ae25aff6f290815216fcd4ced)
Ecuación radial[editar]
![{\displaystyle {\frac {2m}{\hbar ^{2}}}(E-V)-{\frac {1}{R}}{\frac {1}{r^{2}}}{\frac {\partial }{\partial r}}(r^{2}{\frac {\partial R}{\partial r}})=l(l+1)}](https://wikimedia.org/api/rest_v1/media/math/render/svg/6043200208048f7e33d265af96cbdd4378860802)
Momentum angular[editar]
![{\displaystyle \ {\vec {L}}={\vec {r}}\times {\vec {p}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d4f055509e4391532ed1fcbb7569cdcec8c0bd92)
![{\displaystyle {\hat {L}}={\frac {\hbar }{i}}({\vec {r}}\times \nabla )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/50af6d0e0ba687b4f999c641348177f52b2cec07)
![{\displaystyle \nabla ={\vec {u}}_{r}{\frac {\partial }{\partial r}}+{\vec {u}}_{\theta }{\frac {1}{r}}{\frac {\partial }{\partial \theta }}+{\vec {u}}_{\phi }{\frac {1}{rsin\theta }}{\frac {\partial }{\partial \phi }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/3fdac4159adaa877e2f64a9efc0b37f5c067e4a5)
![{\displaystyle {\hat {L}}={\frac {\hbar }{i}}r[({\vec {u}}_{r}\times {\vec {u}}_{r}){\frac {\partial }{\partial r}}+({\vec {u}}_{\theta }\times {\vec {u}}_{r}){\frac {1}{r}}{\frac {\partial }{\partial \theta }}+({\vec {u}}_{\phi }\times {\vec {u}}_{r}){\frac {1}{rsin\theta }}{\frac {\partial }{\partial \phi }}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/e29a678e8045e566df0a0369daf3b001f2ee910b)
![{\displaystyle {\hat {L}}={\frac {\hbar }{i}}[{\vec {u}}_{\phi }{\frac {\partial }{\partial \theta }}+{\vec {u}}_{\theta }{\frac {1}{sin\theta }}{\frac {\partial }{\partial \phi }}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/cb67f6ac84875f46603f09bc8611b2d95648eae3)
![{\displaystyle L^{2}=-\hbar ^{2}[{\frac {1}{sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial }{\partial \theta }})+{\frac {1}{sin^{2}\theta }}{\frac {\partial ^{2}}{\partial \phi ^{2}}}]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/bebd0ef89ef9ae11aca648b1c1085a60f6b5b9fe)
![{\displaystyle {\frac {1}{sin\theta }}{\frac {\partial }{\partial \theta }}(sin\theta {\frac {\partial Y}{\partial \theta }})+{\frac {1}{sin^{2}\theta }}{\frac {\partial ^{2}Y}{\partial \phi ^{2}}}=-l(l+1)Y}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c1cbdb70873ab2aa679dbdb4d1769c675ab24b54)
![{\displaystyle L^{2}Y=\hbar ^{2}l(l+1)Y\to L^{2}\psi =\hbar ^{2}l(l+1)\psi }](https://wikimedia.org/api/rest_v1/media/math/render/svg/bbe56599d4cdee4ec922677bfc17c688d0f4bf34)
![{\displaystyle L_{z}={\frac {\hbar }{i}}{\frac {\partial \psi }{\partial \phi }}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/bca8434a8bc74db71372feb6f6d08ff67d8b9ebd)
Átomo de hidrógeno[editar]
![{\displaystyle R_{nl}(r)Y_{l}^{m}(\theta ,\phi )=\psi _{nlm}(r,\theta ,\phi )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/21901a0af8ba7a091ebd5ba0a214c14fbbdf7af8)
![{\displaystyle \ \psi _{nlm}=R(r)\Theta (\theta )\Phi (\phi )}](https://wikimedia.org/api/rest_v1/media/math/render/svg/beb356c9091fbccedb6d9d8386851b7e08d19e8b)
![{\displaystyle \ \psi _{nlm}=R(r)AP_{m}^{l}(cos\theta )e^{im\phi }}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a951e755a9eccf37bce135551d9817d8779880aa)