30-04-2021

Neon Atom

Eric Schiff, chair of the department of physics at Syracuse University, provides this explanation.

Neon (Ne) exists as a colourless, odourless gas and is chemically inert. It has the atomic number 10 in the periodic table and belongs in Group 18, the Noble Gases. It is a non metal with the symbol Ne. Name: Neon Symbol: Ne Atomic Number: 10 Atomic Mass: 20.1797 amu Melting Point:-248.6 °C (24.549994 K, -415.48 °F) Boiling Point:-246.1 °C (27.049994 K, -410.98 °F) Number of Protons/Electrons: 10 Number of Neutrons: 10 Classification: Noble Gas Crystal Structure: Cubic Density @ 293 K: 0.901 g/cm 3 Color: colorless Atomic Structure. Neon is a chemical element with symbol Ne and atomic number 10. It is in group 18 (noble gases) of the periodic table. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air.

GAS DISCHARGE TUBES emit different colors depending on the element contained inside. Neon signs are orange, like the word physics above.

By definition, the atoms of inert gases such as helium, neon or argon never (well, almost never) form stable molecules by chemically bonding with other atoms. But it is pretty easy to build a gas discharge tubesuch as a neon lightwhich reveals that inertness is a relative matter. One need apply only a modest electric voltage to electrodes at the ends of a glass tube containing the inert gas and the light begins to glow.
It's much easier to explain why neon isn't inert in a discharge tube than it is to explain why it is inert to chemical reactions. The voltage across a discharge tube will accelerate a free electron up to some maximum kinetic energy. The voltage must be large enough so that this energy is more than that required to 'ionize' the atom. An ionized atom has had an electron plucked out of an orbital to make it a 'free' particle, and the atom it leaves behind has become a positively charged ion. The resulting plasma of charged ions and electrons carries the electric current between the tube's electrodes.

The photo (above) shows a gas discharge sign designed by Sam Sampere of Syracuse University. This sign incorporates a neon discharge tube (the orange word 'Physics') and mercury discharge tubes (the blue word 'Experience' and the outer frame). The sculpture at the bottom of the sign represents the electric and magnetic fields of light. The white and yellow sine waves in the sculpture are actually fluorescent lights. These fluorescent lights are mercury discharge tubes with special coatings on their inner walls. The ultraviolet light emitted by the mercury discharge inside a tube is absorbed by the coating, which subsequently emits light of a different color (and with a lower photon energy). Depending on the exact material of the coating, a whole range of colors can be obtained.

So why do these gas discharges emit light? As an alternative to being removed by an energetic collision, an electron on an atom can be excited. One speaks of the electron as having been promoted to an orbital of higher energy. When the electron eases back down to its original orbital, a particle of light (a photon) carries away the energy of excitationand the discharge tube glows! A photon's energy (its wavelength or color) depends on the energy difference between orbitals. A given atom can emit photons at many energies corresponding to its different pairs of orbitals. This series of photon energiesthe emission lines to a spectroscopistis unique to a particular atom. As can be seen in the sign, the mercury discharge tubes have a very different hue than the neon discharge tube does. The inert gas helium was actually discovered this way, and observations of sunlight revealed a series of photon energies that had never before been seen in discharges on the earth.

The chemical inertness of certain gases is subtler to explain. Generally speaking, when two atoms come into proximity, the highest energy, or valence, orbitals of the atoms change substantially and the electrons on the two atoms reorganize. If this reorganization lowers the total energy of the electrons involved, a chemical bond can form. For ordinary, non-inert atoms, the electrons are relatively pliable and bonds often form. The electrons in inert gases, however, are relatively resistant to this proximity effect, so these gases very rarely bond to form molecules.

The apparent contradiction between the inertness of a gas (with respect to chemical bonding) and its liveliness (in a glow discharge) is an example of a broader phenomenon that we might call the unbearable inertness of matter. An atom may be considered as an inert, unreactive particle as long as the energy of its interaction with other particles (including photons) is small enough so that the atom's electrons don't get excited. Atoms of inert gases like neon are the most tenaciously laid back. Still, as interaction energies increase, even they lose their inertness, and we ultimately get a soup of inert nuclei and electronsa highly excited plasma. Increase the energy more (actually, a lot more), and the nuclei are no longer so inert either. We get instead a brew of nucleonsas in a neutron star. Step up the energy some more, and we enter the realm of quarks. Here even nucleons are no longer inertand we have returned to the incredibly energetic, primordial conditions that prevailed shortly after the big bang.
Answer originally posted December 4, 2001.

About Neon

Neon Atoms Are Attracted To Each Other By

Neon is a noble gas, and perhaps surprisingly, the fifth most plentiful element in the cosmos (after hydrogen, helium, oxygen and carbon); however, its abundance in Earth’s atmosphere is rather rare (about 18 ppm). No known neutral compounds exist with this chemically unreactive element, and therefore neon cannot affix itself to any solids. It is theorized that neon’s volatile nature with high vapor pressure and relative lightness caused the element to escape in large quantities during the formation of Earth as a planet, under the sun’s blanket of heat. Neon was discovered, as with many noble gases, through fractional distillation of liquefied air in 1898 by British chemists Sir William Ramsay and Morris Travers. In fact, this rare atmospheric element was discovered a mere two weeks after another noble gas, krypton. This method of isolating atmospheric elements was clearly fruitful as Ramsay won the Nobel Prize for Chemistry in 1904 for these numerous discoveries.

Neon is an iconic element and can only be produced through fractional distillation of liquefied air. Because of these two factors, neon can be a relatively expensive element to produce and purchase. Its attractive characteristics in lighting applications are enabled by its activation (atom separation and recombination in a vacuum tube) at nominal voltages and currents in modern electrical systems. Download java 1.7 mac. Neon itself is reddish-orange when activated, but lighting apparatuses can replicate a number of colors in the visible spectrum when neon is mixed with other gases. For this reason, neon was the precursor of today’s modern plasma displays and TV screens. Lesser known applications include neon as a refrigerant in its liquid form. It has 40 times the refrigerant capacity of liquid helium and three times the refrigerant capacity of liquid hydrogen.

Neon has three stable isotopes: ²⁰Ne, ²¹Ne, and ²²Ne. ²¹Ne and ²²Ne are both primordial (have existed since the formation of the earth) and nucleogenic (produced through naturally-occurring nuclear reactions). The nucleogenic instances of neon isotopes are known to be a result of nuclear reactions, primarily with ²⁴Mg and ²⁵Mg. ²⁰Ne, on the other hand, is known to be primordial but not nucleogenic. The relative sources of ²⁰Ne, while the most abundant of the three isotopes on earth, is debated to this day. Due to the enriched amounts of ²⁰Ne in volcanic gas and its presence in diamonds, some theorize that there may exist a “solar neon reservoir” in the Earth. Throughout this scientific discovery and analysis process of all three naturally-occurring neon isotopes, it is now being theorized that neon can be useful in determining cosmic exposure ages of meteorites and rocks located on a planetary body’s surface.

Neon Properties

Neon is a Block P, Group 18, Period 10 element. The number of electrons in each of Neon's shells is 2, 8 and its electronic configuration is 1s² 2s² 2p⁶. In its elemental form neon's CAS number is 7440-01-9. The neon atom has a covalent radius of 58.pm and it's Van der Waals radius is 154.pm. Neon is found in small amounts in the Earth's atmosphere and is commercially produced by cryogenic fractional distillation of liquefied air. Neon was discovered and first isolated by Sir William Ramsay and Morris W. Travers in 1898. The origin of the name comes from the Greek word neon meaning new.

Neon information, including technical data, properties, and other useful facts are specified below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity, and thermal properties are included.

Symbol:	Ne
Atomic Number:	10
Atomic Weight:	20.18
Element Category:	noble gases
Group, Period, Block:	18, 2, p
Color:	colorless
Other Names:	Neo

Melting Point:	-248.59°C, -415.462°F, 24.56 K
Boiling Point:	-246.053°C, -410.895°F, 27.097 K
Density:	1442 (5 K) kg·m³
Liquid Density @ Melting Point:	1.207 g·cm³
Density @ 20°C:	0.0009 g/cm³
Density of Solid:	1444 kg·m³
Specific Heat:	N/A
Superconductivity Temperature:	N/A
Triple Point:	24.556 K, 43.37 kPa
Critical Point:	44.4918 K, 2.7686 MPa
Heat of Fusion (kJ·mol^-1):	0.324
Heat of Vaporization (kJ·mol^-1):	1.736
Heat of Atomization (kJ·mol^-1):	0
Thermal Conductivity:	49.1x10-3 W·m^-1·K^-1
Thermal Expansion:	N/A
Electrical Resistivity:	N/A
Tensile Strength:	N/A
Molar Heat Capacity:	5R/2 = 20.786 J·mol^-1·K^-1
Young's Modulus:	N/A
Shear Modulus:	N/A
Bulk Modulus:	654 GPa
Poisson Ratio:	N/A
Mohs Hardness:	N/A
Vickers Hardness:	N/A
Brinell Hardness:	N/A
Speed of Sound:	(gas, 0 °C) 435 m·s^-1
Pauling Electronegativity:	N/A
Sanderson Electronegativity:	4.5
Allred Rochow Electronegativity:	4.84
Mulliken-Jaffe Electronegativity:	3.98 (12.5% s orbital)
Allen Electronegativity:	4.787
Pauling Electropositivity:	N/A
Reflectivity (%):	N/A
Refractive Index:	1.000067

Electrons:	10
Protons:	10
Neutrons:	10
Electron Configuration:	[He]2s²2p⁶
Atomic Radius:	N/A
Atomic Radius, non-bonded (Å):	1.54
Covalent Radius:	58 pm
Covalent Radius (Å):	0.62
Van der Waals Radius:	154 pm
Oxidation States:	1, 0
Phase:	Gas
Crystal Structure:	face-centered cubic
Magnetic Ordering:	diamagnetic
Electron Affinity (kJ·mol^-1)	Not stable
1^st Ionization Energy:	2080.7 kJ·mol^-1
2^nd Ionization Energy:	3952.3 kJ·mol^-1
3^rd Ionization Energy:	6122 kJ·mol^-1

Neon Atomic Structure

CAS Number:	7440-01-9
EC Number:	231-110-9
MDL Number:	MFCD00011136
Beilstein Number:	N/A
SMILES Identifier:	[Ne]
InChI Identifier:	InChI=1S/Ne
InChI Key:	GKAOGPIIYCISHV-UHFFFAOYSA-N
PubChem CID:	23935
ChemSpider ID:	22377

Earth - Total:	0.50E-8 cm^3/g
Mercury - Total:	N/A
Venus - Total:	49E-8 cm^3/g
Earth - Seawater (Oceans), ppb by weight:	0.12
Earth - Seawater (Oceans), ppb by atoms:	0.037
Earth - Crust (Crustal Rocks), ppb by weight:	3
Earth - Crust (Crustal Rocks), ppb by atoms:	3
Sun - Total, ppb by weight:	1000000
Sun - Total, ppb by atoms:	70000
Stream, ppb by weight:	N/A
Stream, ppb by atoms:	N/A
Meterorite (Carbonaceous), ppb by weight:	N/A
Meterorite (Carbonaceous), ppb by atoms:	N/A
Typical Human Body, ppb by weight:	N/A
Typical Human Body, ppb by atom:	N/A
Universe, ppb by weight:	1300000
Universe, ppb by atom:	80000

Discovered By:	William Ramsay & Morris Travers
Discovery Date:	1898
First Isolation:	William Ramsay & Morris Travers (1898)

Health, Safety & Transportation Information for Neon

Neon is not toxic and is chemically inert, and thus poses minimal environmental or health threats. At room temperature, neon is typically only harmful when its presence leads to displacement of oxygen in the air, creating potential for asphyxiation. Liquid neon is extremely cold; therefore skin contact with the liquid can cause frostbite, and should be avoided.

Safety Data
Material Safety Data Sheet	MSDS
Signal Word	Warning
Hazard Statements	H280
Hazard Codes	N/A
Risk Codes	N/A
Safety Precautions	N/A
RTECS Number	N/A
Transport Information	N/A
WGK Germany	3
Globally Harmonized System of Classification and Labelling (GHS)

Neon Isotopes

Neon has three stable isotopes: ²⁰Ne, ²¹Ne, and ²²Ne

Neon Atom Drawing

Nuclide	Isotopic Mass	Half-Life	Mode of Decay	Nuclear Spin	Magnetic Moment	Binding Energy (MeV)	Natural Abundance (% by atom)
¹⁶Ne	16.025761(22)	9E-21 s [122(37) keV]	2p to ¹⁴O	0+	N/A	94.75	-
¹⁷Ne	17.017672(29)	109.2(6) ms	ß⁺ + p to ¹⁶O; ß⁺ + a to ¹³N; ß⁺ to ¹⁷F	1/2-	N/A	110.28	-
¹⁸Ne	18.0057082(3)	1.672(8) s	EC to ¹⁸F	0+	N/A	129.54	-
¹⁹Ne	19.0018802(3)	17.296(5) s	EC to ¹⁹F	1/2+	-1.885	141.34	-
²⁰Ne	19.9924401754(19)	STABLE	-	0+	0	157.81	90.48
²¹Ne	20.99384668(4)	STABLE	-	3/2+	-0.661796	164.95	0.27
²²Ne	21.991385114(19)	STABLE	-	0+	0	174.9	9.25
²³Ne	22.99446690(11)	37.24(12) s	ß^- to ²³Na	5/2+	-1.08	180.18	-
²⁴Ne	23.9936108(4)	3.38(2) min	ß^- to ²⁴Na	0+	N/A	189.19	-
²⁵Ne	24.997737(28)	602(8) ms	ß^- to ²⁵Na	(3/2)+	N/A	193.54	-
²⁶Ne	26.000461(29)	197(1) ms	ß^- to ²⁶Na; ß^- + n to ²⁵Na	0+	N/A	198.83	-
²⁷Ne	27.00759(12)	32(2) ms	ß^- to ²⁷Na; ß^- + n to ²⁶Na	(3/2+)#	N/A	200.38	-
²⁸Ne	28.01207(16)	18.3(22) ms	ß^- to ²⁸Na; ß^- + n to ²⁷Na	0+	N/A	203.8	-
²⁹Ne	29.01939(29)	15.6(5) ms	ß^- to ²⁹Na	(3/2+)#	N/A	205.36	-
³⁰Ne	30.02480(61)	5.8(2) ms	ß^- to ³⁰Na	0+	N/A	208.78	-
³¹Ne	31.03311(97)#	3.4(8) ms	ß^- to ³¹Na; ß^- + n to ³⁰Na	7/2-#	N/A	208.48	-
³²Ne	32.04002(86)#	3.5(9) ms	ß^- + n to ³¹Na; ß^- to ³²Na	0+	N/A	210.03	-
³³Ne	33.04938(86)#	<260 ns	Unknown	7/2-#	N/A	209.73	-
³⁴Ne	34.05703(87)#	1# ms [>1.5 µs]	Unknown	0+	N/A	210.35	-