Mastering Electron Positions

Hund's Rule, the Pauli exclusion principle, and the Aufbau principle.

Orbitals are fixed locations where electrons are likely to be found within an atom. Their location is defined by their quantum number.

The first quantum number, n, represents the electron shell and gives the energy levels of the atomic structure.

<p>The analogy of a hotel can be used to explain electron shells by comparing them to floors of the hotel. The lower the floor (i.e. the smaller the value of n), the lower the energy of that electron shell.</p> Signup and view all the answers

<p>The second quantum number, l, represents the subshells within each electron shell. These subshells have different shapes depending on their energy level.</p> Signup and view all the answers

<p>The third quantum number, ml, represents the number of orbitals per subshell. Each of these orbitals can hold exactly two electrons.</p> Signup and view all the answers

<p>The first quantum number (n) represents the shell.</p> Signup and view all the answers

<p>The second quantum number (l) represents the subshell.</p> Signup and view all the answers

<p>The third quantum number (ml) represents the number of orbitals in a subshell.</p> Signup and view all the answers

<p>The fourth quantum number (ms) represents the electron spin.</p> Signup and view all the answers

<p>The Pauli exclusion principle states that no two electrons can have the exact same quantum numbers.</p> Signup and view all the answers

<p>Hund's rule states that electrons will fall into empty orbitals of the same energy before electrons begin to pair up into the same orbital, and that these electrons falling into empty orbitals will all have the same spin value.</p> Signup and view all the answers

<p>The Aufbau Principle states that electrons fill lower energy orbitals before moving to higher energy orbitals.</p> Signup and view all the answers

<p>With these three rules, we can determine the order in which subshells and shells are filled, exactly how electrons fill each subshell, and how they fill a single orbital.</p> Signup and view all the answers

<p>The Pauli exclusion principle states that no two electrons in an atom can have the exact same quantum numbers.</p> Signup and view all the answers

<p>The fourth quantum number is ms, which gives the spin of an electron. It can come in a value of either 1/2 (spin-up) or -1/2 (spin-down).</p> Signup and view all the answers

<p>Hund's rule states that electrons will fall into empty orbitals of the same energy before electrons begin to pair up into the same orbital. This helps determine the filling of orbitals in subshells containing multiple orbitals.</p> Signup and view all the answers

<p>The Aufbau principle states that electrons will fill the lower energy level orbitals before moving to higher energy orbitals. It determines the filling order of subshells.</p> Signup and view all the answers

<p>In general, the energy levels of orbitals increase with the first and second quantum numbers, which are the shell and the subshell.</p> Signup and view all the answers

<p>According to the diagram provided, the subshells are filled in the order 1s, 2s, 2p, 3s, 3p, 4s, 3d, and so forth.</p> Signup and view all the answers