Unit - Quantum Mechanical Model of Atom Evaluate yourself: ) Given: accelerated potential = keV The kinetic energy of the electron = the energy due to accelerating potential. mv eV mv eV m v meV mv meV mv meV de Broglie wavele ⇒ ⇒ ( ) ngth h mv h meV λ λ ⇒ m = mass of the electron = . × – kg h = Planck constant = . × – Js eV = .
× – J λ λ Js kg keV JS × × kgJ m λ [ ( ) . ] Js J kg J kg s kgm s kg s m . Given ∆ v = . × ms – ∆ x = ?
According to Heisenberg's uncertainty principle, ∆ ∆≥ x p h π h kgm s h x p π π ∆ ∆≥ ∆ ∆≥ ⇒∆≥ x m v x kgm s kg ms x m ⇒∆≥ 11th Std Chemistry 11th Std Chemistry - - - - . n = l = , , , ∴ sub shells s, p, d & f. l = m l = ⇒ one 4s orbital. l = m l = – , , + ⇒ three 4p orbitals.
l = m l = – , – , , + , + ⇒ five 4d orbitals. l = m l = – , – , – , , + , + , + ⇒ seven 4f orbitals. Over all orbitals are possible. .
Orbital l Radial node n – l – Angular node l Total node n – 3d 4f . E eV n =