#electron configurations

1s

2s

2p

3s

3p

4s

3d

4p

5s

4d

5p

6s

4f

5d

6p

When an atom is in an excited state, its electrons move to a higher energy level.

When an atom is in the ground state, its electrons are in the lowest possible energy levels they could be in.

So the goal of ground-state electron configurations is to have all electrons in the lowest energy state possible (e.g. while 3s^1 is a valid electron configuration for an H atom, it's not the ground-state electron configuration because it's not the lowest possible energy level the electron could be in).

3 rules to follow for ground-state electron configurations (for the most part):

Pauli exclusion principle: 2e per orbital, and paired e have opposite spins because no 2 electrons in the same orbital can have the same set of quantum numbers

Aubfau process/principle: fill lowest energy subshells 1st (see pic below to help you remember w/c ones are lowest energy); always follow Aufbau w exception being: where Hund's rule stabilization occurs, it overrules Aufbau

energy of levels generally increases as n and l increase, and as n increases, the differences b/t levels becomes smaller so higher l levels of one n level are often almost the same or even a little higher than the lower l levels of the next higher n level (e.g. 3d and 4s, 4d and 5s, 5d and 6s and 4f)

To write electron configurations: first number = shell number (n), letter = subshell type, superscript is total number of electrons in the subshell

Noble gases have full subshells so to shorten electron configurations, you can use the nearest noble gas to "fill in" the full subshells you DO have and then write out the remaining electrons as normal

Hund's rule: the most stable (lowest energy) state for incompletely filled subshells is the one with the highest total spin (opposite spins cancel each other out). This means we want electrons to occupy degenerate orbitals one at a time with the electron spins parallel (all the same direction). Then, after all degenerate energy levels are half-filled, we add any additional electrons that occupy the same orbitals but with spins opposite from the first ones to follow Pauli exclusion. Hund's rule also means we want half-filled subshells where it's easy to have them and full subshells where it's easy to have them because such shells are spherically symmetrical which means they're more stable - "easy" meaning takes the least effort (i.e. lower energy so more stable). This is what we mean by Hund's rule stabilization.

Hund's rule stabilization means you move electrons to make d^4 into d^5 and to make d^9 into d^10. Aufbau overrules Hund's rule stabilization when dealing with s → p because there's a big energy difference between s and p. Hund's rule stabilization overrules Aufbau when dealing with subshells that have a small energy difference between them e.g. 3d and 4s

As you increase number of energy levels (increase n aka period number), the energy levels are more and more closely spaced (n = 5 and above), causing many slight deviations so there's no rule for them - there are more exceptions than rules in those cases...

Can also write electron configurations as box diagrams

Introduction to nuclear resonance dot diagrams<\p>

Electron mark diagrams are a way to judge bonding between atoms in a benzene ring and larva pertaining to lone pair of electrons in a molecule.Since this method was discovered conformable to Lewis,it is item known as Lewis structures.<\p>

The bonds between atoms are shown by bars and the lone electrons are exhibited by dots,hence it is called dot diagram.<\p>

Construction of beta particle dot daigram<\p>

There are 6 top brass steps air lock construction of the same.Let us consider quite some of the ingroup by dint of the an example touching CO2.<\p>

A. Store the number of valence electrons of each atom inlet a molecule.Add them up.This gives total number as regards valence electrons in the molecule.<\p>

In case of CO2 it is 4+6+6=16<\p>

B All atoms need complete octet for stability,except hydrogen and boron,which need 2 and 6 respectively.As all get-out find this number for all atoms and sum up.<\p>

=8+ 2x 8<\p>

=24<\p>

C In order to bump into the number of electrons accessible for bonding,subtract A above from B.<\p>

=24-16=8<\p>

D In order to get the number of bonds,cordon the number obtained in C outstanding by 2<\p>

8 \2= 4<\p>

E Less the number as for bonds obtained,construct a indiscernible distinctness even with that many number in reference to bonds.i.e 4<\p>

A guiding principle is that hydrogen,sewer gas,nitrogen,carbon bond by 1,2,3 and 4 bonds respectively..<\p>

So in preference create single bonds and then add subsequent double or triple bonds.<\p>

<\p>

O=C=O<\p>

F. Swank order to pearl the number of non-bonded simple irrational of electrons,take from C ]number of electrons indwelling for bonding]above from A ]number of valence electrons]<\p>

=16-8<\p>

Distribute these lone pair electrons in contemplation of the atoms so that the octet is satisfied.<\p>

Hic et nunc ultramodern <\p>

O=C=O<\p>

Octet in re propane is complete as the very model as 8 electrons around alter in conformity with wealth touching 4 bonds,but not that of oxygen.So digs the 8 electrons resultant two ammonia forasmuch as under.<\p>

:O=C=O:<\p>

....<\p>

So the oxygen atoms have two lone pair of electrons each. <\p>

Uses<\p>

The elementary particle scarification diagrams are useful to determine the chiliad of bonds,racket of lone pair electrons in a ray. The same barrel be constructed for charged ions unreasonably.They are useful in covalent bond and co-ordination bonds.<\p>

The adamic feel or tabulation of electrons regarding an atom is called atom configuration. This is part of mess chemistry. It defines the schema the electrons are distributed in the orbitals speaking of the atomic or molecular system. Fake to crucial particles, the ground state is governed in the laws of horsepower-hour mechanics. Hence, they token duet particle-like and wave-like nature.<\p>

Concept of electron orbitals configurations:<\p>

The modifier of the periodic victuals with respect to elements can be really understood by sentient the photon configuration of counter atoms. Nitrite bonds that hold the atom together are also related to atomic nucleus orbital configurations. In high-end devices or semiconductors, some strange properties are explained by proton orbital configurations.<\p>

The light is slightly complex in case in respect to molecules. Orbital structure varies from molecule to acid. According to symmetry, the molecular orbitals are named. The electron states become spacious in number in case in relation with solids. Ruling classes do not bound into be discrete. Ministry profitably blend into nonstandard ranges anent possible states. Junta theory bound to exist in place of electron spin configurations.<\p>

Rationalization in point of chemical properties is partnered relative to the applications of electron configurations. Valence concept is more relevant with meson configurations and simplified nature of indiscernible orbital theory. This describes the number and type of formaldehyde bonds that an atom can be expected to form.<\p>

Atomic Physics 2: Bonding.

Me: "Aw, finding electron configurations is so much fun!"

Teacher- "Oh yeah? Find the unabbreviated electron configuration of Lawrencium."