What are the three rules thar govern the filling of atomic orbitals by electrons?

Answer 1

1 type s orbital → max 2 electrons

3 type p orbitals → max 6 electrons

5 type d orbitals → max 10 electrons

7 type f orbitals → max 14 electrons

9 type g orbitals → max 18 electrons

[edit] Aufbau principle

In the ground state of an atom (the condition in which it is ordinarily found), the electron configuration generally follows the Aufbau principle. According to this principle, electrons enter into states in order of the states' increasing energy; i.e., the first electron goes into the lowest-energy state, the second into the next lowest, and so on.

A pair of electrons with identical spins has slightly less energy than a pair of electrons with opposite spins. Since two electrons in the same orbital must have opposite spins, this causes electrons to prefer to occupy different orbitals. This preference manifests itself if a subshell with l > 0 (one that contains more than one orbital) is less than full. For instance, if a p subshell contains four electrons, two electrons will be forced to occupy one orbital, but the other two electrons will occupy both of the other orbitals, and their spins will be equal. This phenomenon is called Hund's rule.

Hund's rules

Hund's rules, (occasionally called the "bus seat rule") refer to a simple set of rules used to determine which is the term symbol that corresponds to the ground state of a multi-electron atom. They are named in honour of Friedrich Hund who contributed Hund's Rule, rule two as listed here.

The four rules are:

1. Electrons can occupy energy levels only above the 2s orbital total orbital.

2. The term with maximum multiplicity (maximum ) has the lowest energy level.

3. For a given multiplicity, the term with the largest value of has the lowest energy in an orbital.

4. For atoms with less than half-filled shells, the level with the lowest value of lies lowest in energy. Otherwise, if the outermost shell is more than half-filled, the term with highest value of is the one with the lowest energy.

Answer 2

Aufbau principle- build from the bottom up, and fill lowest energy levels first

Pauli exclusion principle- each orbital may have only two electrons, with opposite spins

Hund's rule- each orbital of a level must each have one electron before any have two

Answer 3

RULES FOR FILLING MOLECULAR ORBITALS

Aufbau's principle

molecular orbitals with electrons are filled in the increasing order of their energies.this principle is called Aufbau's principle

Pauli's exclusion principle

A molecular orbital like atomic orbital can accommodate only two electrons with opposite spins as required bu Pauli's exclusion principle

Hund's rule of maximum multiplicity

in molecular orbital no electron pairing takes place until all the available orbitals of identical energy are singly occupied.this is Hund's rule of maximum multiplicity.

Answer 4

The aufbau principle is the general rule describing the energy order of orbitals and therefore the order in which they are filled in the elements.

A single orbital can hold a maximum of 2 electrons with opposite spin - this is Pauli's exclusion principle.

Answer 5

Aufbau principle, Pauli principle, and Hund's principle.

Answer 6

aufbau priciple, the Pauli exclusion principle, and Hund's rule

Answer 7

Refer to the related links for a Wikibook article on the rules for filling atomic orbitals.