The basics of atoms - Revision history

Apm: added * Atomic orbitals

2021-06-02T18:01:41Z

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	* Sheets can be bent convex (or concave depending on the onlooking side) by replacing some hexagons with pentagons, squares or even triangles ([[Buckyballs]] in general; and cones).		* Sheets can be bent convex (or concave depending on the onlooking side) by replacing some hexagons with pentagons, squares or even triangles ([[Buckyballs]] in general; and cones).
	* Sheets can be bent hyperbolic by replacing some hexagons with heptagons, octagons, ... (Foam like structures e.g. DLC diamond like carbon)		* Sheets can be bent hyperbolic by replacing some hexagons with heptagons, octagons, ... (Foam like structures e.g. DLC diamond like carbon)

			== Related ==

			* [[Atomic orbitals]]

Apm: /* Which elements make good "construction kit building blocks" and why */ fixed link to what is now coordinate bonds

2021-05-15T13:42:18Z

Which elements make good "construction kit building blocks" and why: fixed link to what is now coordinate bonds

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	=== Which elements make good "construction kit building blocks" and why ===		=== Which elements make good "construction kit building blocks" and why ===

	* Elements with too many electrons in the outermost shell (more than four of the maximum eight) have them forming [[lone pair]]s. These can no longer form really strong [[covalent bond]]s. This makes it harder to impossible to form three dimensional networks with these elements only. One may get only sheets or chains instead. Repulsive electron cloud lone pairs are useful though everywhere where we do want surfaces where almost nothing shall adhrere to. (See: [[Passivation]]). There are some cheavats with weaker [[~~coordinative bonds~~]].		* Elements with too many electrons in the outermost shell (more than four of the maximum eight) have them forming [[lone pair]]s. These can no longer form really strong [[covalent bond]]s. This makes it harder to impossible to form three dimensional networks with these elements only. One may get only sheets or chains instead. Repulsive electron cloud lone pairs are useful though everywhere where we do want surfaces where almost nothing shall adhrere to. (See: [[Passivation]]). There are some cheavats with weaker [[coordinate bond]]s.
	* Elements with too few electrons in their outermost shell (less than four) may have their orbitals rearrange themselves into geometries that are different from tetrapodal. This too can make it harder to form three dimensional networks with these elements only. Prime example: The element [[Boron]].		* Elements with too few electrons in their outermost shell (less than four) may have their orbitals rearrange themselves into geometries that are different from tetrapodal. This too can make it harder to form three dimensional networks with these elements only. Prime example: The element [[Boron]].
	* Elements with exactly the right amount of electrons (exactly four) like e.g. carbon (and silicon) can bond to other atoms in all four non-coplanar tetrapodal directions and can thus form three dimensional crystal structures on their own. Not just sheets or chains. Prime examples for tightly meshed 3D networks of that kind are diamond crystals, silicon crystals and silicon carbide (aka [[moissanite]]) crystals.		* Elements with exactly the right amount of electrons (exactly four) like e.g. carbon (and silicon) can bond to other atoms in all four non-coplanar tetrapodal directions and can thus form three dimensional crystal structures on their own. Not just sheets or chains. Prime examples for tightly meshed 3D networks of that kind are diamond crystals, silicon crystals and silicon carbide (aka [[moissanite]]) crystals.

Apm: improvement of intro - more explicit & redundant

2020-09-09T17:25:40Z

improvement of intro - more explicit & redundant

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	Up: [[Intuitive feel]]		Up: [[Intuitive feel]]

	In the context of their usage as bottom up construction kit elements.		This is about the basics of atoms in the context of their usage as bottom up construction kit elements.

	= How do atoms work and what shape do they have ? =		= How do atoms work and what shape do they have ? =

Apm: added brief intro about context

2020-09-09T17:24:41Z

added brief intro about context

← Older revision		Revision as of 19:24, 9 September 2020
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	Up: [[Intuitive feel]]		Up: [[Intuitive feel]]

			In the context of their usage as bottom up construction kit elements.

	= How do atoms work and what shape do they have ? =		= How do atoms work and what shape do they have ? =

Apm: /* Triangular arrangement of hybrid orbitals */ some improvements

2020-09-09T17:22:32Z

Triangular arrangement of hybrid orbitals: some improvements

Apm: /* Tetrapodal arrangement of electron clouds -- that then form bonds between atoms */ ahere => adhere & explanation why non-planarity is useful

2020-09-09T17:00:31Z

Tetrapodal arrangement of electron clouds -- that then form bonds between atoms: ahere => adhere & explanation why non-planarity is useful

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	but that instead one needs to add up some of the electron cloud shapes solutions to get the the electron cloud shape that is actually physically present.</small>		but that instead one needs to add up some of the electron cloud shapes solutions to get the the electron cloud shape that is actually physically present.</small>

	* Orbitals filled with two electrons from the host atom (as depicted here) are called "lone pairs" and repel lone pairs from other atoms.		* Orbitals filled with two electrons from the same host atom (as depicted here) are called "lone pairs" and repel lone pairs from other atoms.
	* Orbitals filled with one electron from the host atom and one electron from a neighbouring atoms merge together and are called bonding "molecular orbitals".		* Orbitals filled with one electron from the same host atom and one electron from a neighbouring atoms like to merge together and are called bonding "molecular orbitals".
	* In case too many electrons are missing (sometimes the case with elements to the left of carbon in the periodic table) the geometric arrangement of electron clouds can change. Details elsewhere.		* In case too many electrons are missing (sometimes the case with elements to the left of carbon in the periodic table) the geometric arrangement of electron clouds can change. Details [[electron deficiency bond\|elsewhere]].

	The four orbitals in the tetrapodal geometry do not lie in a common plane (they are not coplanar).		The four orbitals in the tetrapodal geometry do not lie in a common plane (they are not coplanar). <br>
			This is very useful if one wants to build stiff that goes beyond just planar sheets (and linear chains).

	=== Which elements make good "construction kit building blocks" and why ===		=== Which elements make good "construction kit building blocks" and why ===

	* Elements with too many electrons in the outermost shell (more than four of the maximum eight) have them forming [[lone pair]]s. These can no longer form really strong [[covalent bond]]s. This makes it harder to impossible to form three dimensional networks with these elements only. One may get only sheets or chains instead. Repulsive electron cloud lone pairs are useful though everywhere where we do want surfaces where almost nothing shall ~~ahrere~~ to. (See: [[Passivation]]). There are some cheavats with weaker [[coordinative bonds]].		* Elements with too many electrons in the outermost shell (more than four of the maximum eight) have them forming [[lone pair]]s. These can no longer form really strong [[covalent bond]]s. This makes it harder to impossible to form three dimensional networks with these elements only. One may get only sheets or chains instead. Repulsive electron cloud lone pairs are useful though everywhere where we do want surfaces where almost nothing shall adhrere to. (See: [[Passivation]]). There are some cheavats with weaker [[coordinative bonds]].
	* Elements with too few electrons in their outermost shell (less than four) may have their orbitals rearrange themselves into geometries that are different from tetrapodal. This too can make it harder to form three dimensional networks with these elements only. Prime example: The element [[Boron]].		* Elements with too few electrons in their outermost shell (less than four) may have their orbitals rearrange themselves into geometries that are different from tetrapodal. This too can make it harder to form three dimensional networks with these elements only. Prime example: The element [[Boron]].
	* Elements with exactly the right amount of electrons (exactly four) like e.g. carbon (and silicon) can bond to other atoms in all four non-coplanar tetrapodal directions and can thus form three dimensional crystal structures on their own. Not just sheets or chains. Prime examples for tightly meshed 3D networks of that kind are diamond crystals, silicon crystals and silicon carbide (aka [[moissanite]]) crystals.		* Elements with exactly the right amount of electrons (exactly four) like e.g. carbon (and silicon) can bond to other atoms in all four non-coplanar tetrapodal directions and can thus form three dimensional crystal structures on their own. Not just sheets or chains. Prime examples for tightly meshed 3D networks of that kind are diamond crystals, silicon crystals and silicon carbide (aka [[moissanite]]) crystals.

Apm: /* Tetrapodal arrangement of electron clouds -- that then form bonds between atoms */

2020-09-09T16:54:59Z

Tetrapodal arrangement of electron clouds -- that then form bonds between atoms

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	The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together adjacent atoms in molecules or crystals or [[crystolecules]].		The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together adjacent atoms in molecules or crystals or [[crystolecules]].
	In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). That is: there are four lobes (four==tetra).		In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). That is: there are four lobes (four==tetra).
	The geometry is depicted in blue here. Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.		The geometry is depicted in blue here. <br><small> Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.</small>

	A more technical term for "electron clouds" is "orbitals". The orbitals that are depicted in blue here are called "hybrid orbitals". <br>		A more technical term for "electron clouds" is "orbitals". The orbitals that are depicted in blue here are called "hybrid orbitals". <br>

Apm: /* Tetrapodal arrangement of electron clouds -- that then form bonds between atoms */

2020-09-09T16:53:55Z

Tetrapodal arrangement of electron clouds -- that then form bonds between atoms

← Older revision		Revision as of 18:53, 9 September 2020
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	The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together adjacent atoms in molecules or crystals or [[crystolecules]].		The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together adjacent atoms in molecules or crystals or [[crystolecules]].
	In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). ~~There~~ are ~~with~~ four lobes (four==tetra).		In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). That is: there are four lobes (four==tetra).
	The geometry is depicted in blue here. Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.		The geometry is depicted in blue here. Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.

Apm: /* Tetrapodal arrangement of electron clouds -- that then form bonds between atoms */ added … link together adjacent atoms in …

2020-09-09T16:52:33Z

Tetrapodal arrangement of electron clouds -- that then form bonds between atoms: added … link together adjacent atoms in …

← Older revision		Revision as of 18:52, 9 September 2020
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	[[File:AE4h.svg\|200px\|thumb\|right\|Tetrapodal electron cloud arrangement (tech term: sp<sup>3</sup>) '''Note:''' This is still a simplified view. The orbitals are actually more bean shaped, overlapping and blurry. But depicting it more realistically would obfuscate the geometric arrangement too much.]]		[[File:AE4h.svg\|200px\|thumb\|right\|Tetrapodal electron cloud arrangement (tech term: sp<sup>3</sup>) '''Note:''' This is still a simplified view. The orbitals are actually more bean shaped, overlapping and blurry. But depicting it more realistically would obfuscate the geometric arrangement too much.]]

	The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together molecules or crystals or [[crystolecules]].		The outermost electron clouds are the most relevant since usually only these take part in [[covalent bond\|covalent]] chemical bonds. Bonds that link together adjacent atoms in molecules or crystals or [[crystolecules]].
	In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). There are with four lobes (four==tetra).		In the elements of concern on this page (see above) the most common arrangement of the outer "electron clouds" is tetrapodal (aka tetrahedral). There are with four lobes (four==tetra).
	The geometry is depicted in blue here. Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.		The geometry is depicted in blue here. Note that the disconnected small lobes and the big lobes that are on exactly 180° opposing sides belong together respectively forming a single electron cloud each.

Apm: /* Tetrapodal arrangement of electron clouds -- that form then bonds between atoms */ word swap

2020-09-09T16:50:57Z

Tetrapodal arrangement of electron clouds -- that form then bonds between atoms: word swap

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	What will not be discussed here are heavier elements like transition metals and beyond which can have quite complicated electron configurations.		What will not be discussed here are heavier elements like transition metals and beyond which can have quite complicated electron configurations.

	== Tetrapodal arrangement of electron clouds -- that form ~~then~~ bonds between atoms ==		== Tetrapodal arrangement of electron clouds -- that then form bonds between atoms ==

	[[File:AE4h.svg\|200px\|thumb\|right\|Tetrapodal electron cloud arrangement (tech term: sp<sup>3</sup>) '''Note:''' This is still a simplified view. The orbitals are actually more bean shaped, overlapping and blurry. But depicting it more realistically would obfuscate the geometric arrangement too much.]]		[[File:AE4h.svg\|200px\|thumb\|right\|Tetrapodal electron cloud arrangement (tech term: sp<sup>3</sup>) '''Note:''' This is still a simplified view. The orbitals are actually more bean shaped, overlapping and blurry. But depicting it more realistically would obfuscate the geometric arrangement too much.]]

← Older revision		Revision as of 19:22, 9 September 2020
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	[[File:AE3h.svg\|150px\|thumb\|right\|Triangular electron cloud arrangement. (tech term: sp<sup>2</sup>) '''Note:''' the fourth orbital is not depicted!]]		[[File:AE3h.svg\|150px\|thumb\|right\|Triangular electron cloud arrangement. (tech term: sp<sup>2</sup>) '''Note:''' the fourth orbital is not depicted!]]

	There are other possible electron cloud arrangements too.		There are other possible electron cloud arrangements too. <br>
	The second most common one is triangular (as depicted here in blue).		The second most common one is triangular (as depicted here in blue).

	The light elements have four outer shell orbitals but only three are depicted here, so one is obviously missing.		The light elements have four outer shell orbitals but only three are depicted here, so one is obviously missing.
	The missing/non-depicted fourth one sticks out vertically both up and down equally from the image-plane.		The missing / non-depicted fourth one sticks out vertically both up and down equally from the image-plane.
	The fourth orbital has no small and big lobe like the three depicted hybrid orbitals have.		The fourth non depicted orbital has no small and big lobe like the three depicted hybrid orbitals have.
	It is a fundamental orbital (a p-orbital ~~- a~~ raw solution from the [[Schrödinger equation\|underlying math]]~~) with~~ two lobes of exactly ~~equal~~ size.		It is a fundamental orbital. It's a p-orbital. A raw solution from the [[Schrödinger equation\|underlying math]].
			The two lobes of the p-orbital have exactly the same size and belong together.

	The three hybrid orbitals lie in the same plane and the fourth (the fundamental) ~~orbital~~ has no preference for facing upwards or downwards. ~~Thus atoms that~~ take on this triangular ~~orbital~~ arrangement ~~cannot~~ form three dimensional structures in a way like the atoms with tetrapodal structure. Instead they can only form two dimensional sheets.		The three (depicted) hybrid orbitals lie in the same plane and the fourth orbital (the fundamental one) has no preference for facing upwards or downwards.
			When elements take on this particular triangular geometry / arrangement of electron clouds (because they can do so like e.g. carbon or because they may have trouble to not do so)
			then they no longer can form three dimensional structures in a way like the atoms with tetrapodal structure do. Instead they can only form two dimensional sheets.
			Not counting curvature into 3D (nanotubes & buckyballs) as proper 3D here.

	Just like in the tetrapodal arrangement also in the triangular arrangement case carbon (and silicon) atoms have the ideal number of electrons to neither form lone pairs (repulsing other lone pairs) nor change orbital arrangement.		Just like in the tetrapodal arrangement also in the triangular arrangement case carbon (and silicon) atoms have the ideal number of electrons to neither form lone pairs (repulsing other lone pairs) nor change orbital arrangement. Thus a prime example for sheets out of atoms in triangular orbital arrangement are sheets made out of carbon.
	Thus a prime example for sheets out of atoms in triangular orbital arrangement are sheets made out of carbon.

	In the simplest, that is fully planar, form this is called a graphene sheet.		In the simplest, that is fully planar, form this is called a graphene sheet.
	Stacks of large graphene sheets form very hard single crystalline graphite.		Stacks of large graphene sheets form very hard single-crystalline graphite.
	Normal pencil mine graphite is ~~polycrystalline~~ allowing the small sheet-flakes to slide over each other making it very soft.		Normal pencil mine graphite is poly-crystalline allowing the small sheet-flakes to slide over each other making it very soft.
	(Side-note: Larger chunks of single crystalline graphite do not occur naturally but can by synthesized today. It is called: HOPG)		<small>(Side-note: Larger chunks of single crystalline graphite do not occur naturally but can by synthesized today. It is called: [[highly ordered pyrolytic graphite\|HOPG]])</small>

	In a graphene sheet the fourth orbital (the non-hybridized fundamental p-orbital) different from the three triangularly arranged hybrid orbitals plays a very special role. Not only sticks it out both sides equally it also shares one bond in three directions simultaneously on each side. All those doublesided p-~~prbitals~~ fuse together to one single giant (double sheeted) molecule orbital spanning over the whole sheet on both sides. This allows electrons to move freely (electric conductivity).		=== Delocalized pi-bonds electron gas ===

			In a graphene sheet the fourth orbital (the non-hybridized fundamental p-orbital) different from the three triangularly arranged hybrid orbitals plays a very special role. Not only sticks it out both sides equally it also shares one bond in three directions simultaneously on each side. All those doublesided p-orbitals fuse together to one single giant (double sheeted) molecule orbital spanning over the whole sheet on both sides. This allows electrons to move freely (electric conductivity).

	Bending graphite sheets by various means can drastically (and usefully) change the electronic properties.		Bending graphite sheets by various means can drastically (and usefully) change the electronic properties.
	From semi-conductivity to very high conductivity (much better than copper or silver).		From semi-conductivity to very high conductivity (much better than even copper or silver).

	The tech term for hybrid orbitals that assume the here describesd triangular shape is: sp<sup>2</sup>.		The tech term for hybrid orbitals that assume the here describesd triangular shape is: sp<sup>2</sup>.
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	* Flat sheets must have all atoms arranged in hexagons.		* Flat sheets must have all atoms arranged in hexagons.
	* Flat sheets occur rolled up into tubular shapes ([[Nanotubes]] in general). Beside various diameters different rolling angles are possible (causing different eletronic properties).		* Flat sheets occur rolled up into tubular shapes ([[Nanotubes]] in general). Beside various diameters different rolling angles are possible (causing different eletronic properties).
	* Sheets can be bent convex (or concave depending on the onlooking side) by replacing some hexagons with pentagons, squares or even triangles ([[Buckyballs]] in general).		* Sheets can be bent convex (or concave depending on the onlooking side) by replacing some hexagons with pentagons, squares or even triangles ([[Buckyballs]] in general; and cones).
	* Sheets can be bent hyperbolic by replacing some hexagons with heptagons, octagons, ... (Foam like structures e.g. DLC)		* Sheets can be bent hyperbolic by replacing some hexagons with heptagons, octagons, ... (Foam like structures e.g. DLC diamond like carbon)