The group eight elements are
• Helium (He)
• Neon (Ne)
• Argon (Ar)
• Krypton (Kr)
• Xenon (Xe)
• Radon (Rn)
The six noble gases are found in group 18 of the periodic table. These elements were considered to be inert gases until the 1960’s because their oxidation number of 0 prevents the noble gases from forming compounds readly. All noble gases have the maximum number of electrons possible in their outer most shell (2 for helium and 8 for all others) making their stable.
Noble gas elements are chemically inactive hence that’s why they are called inert gas elements. Two reason account for chemically inertness of the noble gas elements
1. Small atomic size make them to have high ionization energy hence they are difficult to ionize by loosing electrons
2. Stable electronic configuration
However nowdays, several compounds of noble gas elements such as krypton and xenon are known.
Krypton and xenon can from compounds especially with strong electronegative atoms like flourine and oxygen.
Krypton and xenon at least are large enough to ionize by loosing electrons and form positive ions if reacts with fluorine and oxygen. In their compounds Kr and Xe use oxidation states of 4 and 5
E.g.
Xe + 2F2 --------->XeF4 or 5Xe + 5F2--------->XeF5
Kr + 2F2 --------->KrF4
Xe +2O2 ---------->XeO4
No compounds of He, Ne, and Ar have been discovered. This is because of their small atomic size they are difficult to ionize by loosing electrons even when combine with strong electronegative atoms like fluorine and oxygen.
Helium (He)
Helium has atomic number of 2.
It’s electronic configuration is
1s2
This means two electrons per shell.
It’s crystal structure is Hexagonal with density of 0.1785g/cm3 and it’s colorless.
Uses of Helium
1. Used as a carrier gas in gas chromatography.
2. Helium is used to combine hydrogen and oxygen to make rocket fuel.
3. It’s used in balloons.
4. For material easily contaminated by air, helium is used as a shielding gas in the arc welding process particularly when working with aluminium and copper
5. Used to pressurize and purge system of unwanted gases.
Neon (Ne)
It’s atomic number is 10
The electronic configuration of Neon is
1s2 2s2 2p6.
It’s electrons per shell are 2, 8.
The crystal structure of Neon is cubic with 0.901g/cm3 density and colorless in color.
It’s atomic number is 10
The electronic configuration of Neon is
1s2 2s2 2p6.
It’s electrons per shell are 2, 8.
The crystal structure of Neon is cubic with 0.901g/cm3 density and colorless in color.
Uses of Neon
1. Neon is often used in advertising signs. It produces a bright reddish-orange color. Some other lights with different colors are sometimes called neon lights. However, these are produced with other noble gases.
2. The triple point of neon (the temperature where liquid, gas and solid neon all exist at the same time) is a defining fixed point in the International Temperature Scale of 1990.
3. Liquid neon is often used as a cryogenic refrigerant where the extremely low temperatures requiring liquid helium are not needed. It is more effective than helium so, despite the higher cost, may be more viable.
4. Neon is also used in vacuum tubes, high-voltage indicators, lightning arresters (which protect electrical equipment from lightning strikes), wave meter tubes, television tubes and helium-neon lasers.
Argon (Ar)
It’s atomic number is 18 with electronic configuration of
1s2 2s2 2p6 3s2 3p6
Electron per shell are 2, 8, 8.
It’s crystal structure is cubic with density of 1.784g/cm3 and it’s colorless gas.
1. Neon is often used in advertising signs. It produces a bright reddish-orange color. Some other lights with different colors are sometimes called neon lights. However, these are produced with other noble gases.
2. The triple point of neon (the temperature where liquid, gas and solid neon all exist at the same time) is a defining fixed point in the International Temperature Scale of 1990.
3. Liquid neon is often used as a cryogenic refrigerant where the extremely low temperatures requiring liquid helium are not needed. It is more effective than helium so, despite the higher cost, may be more viable.
4. Neon is also used in vacuum tubes, high-voltage indicators, lightning arresters (which protect electrical equipment from lightning strikes), wave meter tubes, television tubes and helium-neon lasers.
Argon (Ar)
It’s atomic number is 18 with electronic configuration of
1s2 2s2 2p6 3s2 3p6
Electron per shell are 2, 8, 8.
It’s crystal structure is cubic with density of 1.784g/cm3 and it’s colorless gas.
Uses of Argon
1. Argon gas is used in graphite electric burners to prevent the graphite from burning.
2. Crystals of silicon and germanium are grown in the presence of argon.
3. Argon is used to kill pigs humanely if there is an outbreak of some disease on the farm.
4. Occasionally, argon is used to put out fires when it is vital that equipment is not damaged.
1. Argon gas is used in graphite electric burners to prevent the graphite from burning.
2. Crystals of silicon and germanium are grown in the presence of argon.
3. Argon is used to kill pigs humanely if there is an outbreak of some disease on the farm.
4. Occasionally, argon is used to put out fires when it is vital that equipment is not damaged.
Krypton (Kr)
It’s atomic number is 36 with electronic configuration of
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6.
Electrons per shell are 2, 8, 18, 8.
It’s crystal structure is cubic with density of 3.74g/cm3 and it’s a colorless gas.
It’s atomic number is 36 with electronic configuration of
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6.
Electrons per shell are 2, 8, 18, 8.
It’s crystal structure is cubic with density of 3.74g/cm3 and it’s a colorless gas.
Uses of krypton
1. Krypton based bulbs are used in some photography applications because it produces white light under certain conditions. It is usually used in high speed flash photography.
2. This white discharge is also used in colored gas tubes to create a similar effect to a neon sign.
3. Krypton is used in the production and usage of the krypton fluoride laser, which is being used in research for nuclear fusion. It is also suitable for use in high powered laser shows.
4. It is mixed with argon to fill fluorescent lamps. This makes them more energy efficient by reducing the power they require. Unfortunately, this also makes this type of bulb more expensive and reduces the light output. It is also, together with xenon, used in regular light bulbs to reduce filament evaporation and allow it to operate at higher temperatures.
5. An isotope of krypton is used in medical scans (MRI scan) of the airways.
1. Krypton based bulbs are used in some photography applications because it produces white light under certain conditions. It is usually used in high speed flash photography.
2. This white discharge is also used in colored gas tubes to create a similar effect to a neon sign.
3. Krypton is used in the production and usage of the krypton fluoride laser, which is being used in research for nuclear fusion. It is also suitable for use in high powered laser shows.
4. It is mixed with argon to fill fluorescent lamps. This makes them more energy efficient by reducing the power they require. Unfortunately, this also makes this type of bulb more expensive and reduces the light output. It is also, together with xenon, used in regular light bulbs to reduce filament evaporation and allow it to operate at higher temperatures.
5. An isotope of krypton is used in medical scans (MRI scan) of the airways.
Xenon (Xe)
Xenon has atomic number of 54.
It’s electronic configuration is
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
The crystal structure of Xenon is cubic with 5.897g/cm3 density.
Uses of Xenon
1. Used in flash lamps for photographs making.
2. Xenon is also used in xenon arc lamps.
3. Mixture of xenon and neon is used in the cells of plasma televisions.
4. Xenon gas, mixed with oxygen and air, is also used as a general anesthetic and is administered with an anesthesia machine.
5. The medical industry also utilizes two very important isotopes of Xenon, 133X and 129X. 133X is used in nuclear medicine to image vital organs such as the heart, brains and lungs. It can also be used to measure blood flow. 129X is used as a contrast agent in MRI scans.
6. Xenon is also used in bubble chambers and calorimeters, which are used for experiments.
7. It is also used as a propellant in spacecraft that use ion propulsion.
Radon (Rn)
It’s atomic number is 86 with atomic mass 222.0 a.m.u
It’s electronic configuration is
Xe4F146s25d106p6
It’s Crystal structure is cubic with 9.73g/cm3 density at 293k
Xenon has atomic number of 54.
It’s electronic configuration is
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
The crystal structure of Xenon is cubic with 5.897g/cm3 density.
Uses of Xenon
1. Used in flash lamps for photographs making.
2. Xenon is also used in xenon arc lamps.
3. Mixture of xenon and neon is used in the cells of plasma televisions.
4. Xenon gas, mixed with oxygen and air, is also used as a general anesthetic and is administered with an anesthesia machine.
5. The medical industry also utilizes two very important isotopes of Xenon, 133X and 129X. 133X is used in nuclear medicine to image vital organs such as the heart, brains and lungs. It can also be used to measure blood flow. 129X is used as a contrast agent in MRI scans.
6. Xenon is also used in bubble chambers and calorimeters, which are used for experiments.
7. It is also used as a propellant in spacecraft that use ion propulsion.
Radon (Rn)
It’s atomic number is 86 with atomic mass 222.0 a.m.u
It’s electronic configuration is
Xe4F146s25d106p6
It’s Crystal structure is cubic with 9.73g/cm3 density at 293k
Uses of Radon
1. Used in medical for cancer treatment by radiating it.
2. Radon is frequently used as a therapeutic treatment for arthritis in many European counties.
3. It’s used to glow in dark paint.
Properties of the noble gas elements
The atomic and physical properties of the noble gas elements.
1. High ionization energies; the noble gas have largest ionization energy, reflecting their chemical inertness.
2. Have low electronegative value
3. Atomic mass, boiling point and atomic radii increase down the group in the periodic table
4. The increase in density down the group is correlated with the increase in atomic mass.
5. Down the group, atomic radii and interatomic forces increase resulting in a increase melting point, boiling point enthalpy of vaporization and solubility.
6. No color, odor or flavour under ordinary conditions but may form coloured liquids and solids.
1. Used in medical for cancer treatment by radiating it.
2. Radon is frequently used as a therapeutic treatment for arthritis in many European counties.
3. It’s used to glow in dark paint.
Properties of the noble gas elements
The atomic and physical properties of the noble gas elements.
1. High ionization energies; the noble gas have largest ionization energy, reflecting their chemical inertness.
2. Have low electronegative value
3. Atomic mass, boiling point and atomic radii increase down the group in the periodic table
4. The increase in density down the group is correlated with the increase in atomic mass.
5. Down the group, atomic radii and interatomic forces increase resulting in a increase melting point, boiling point enthalpy of vaporization and solubility.
6. No color, odor or flavour under ordinary conditions but may form coloured liquids and solids.
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