Interesting Facts:

• This Group was originally named the "inert gases"

Name Symbol Atomic Boiling Max. Avail. Amt. in the Approx

Helium He 2 -268.9 6,000 5.2 PPM $ .10

Neon Ne 10 -246.07 6,000 18.2 PPM $ 1.00

Argon Ar 18 -185.88 6,000 7600 PPM $ .10

Krypton Kr 36 -156.6 1,350 1.1 PPM $ 3.00

Xenon Xe 54 -108.06 800 0.036 PPM $11.00

Chemical Properties:

The noble gases are relatively nonreactive. This is because they have a complete valence shell. They have little tendency to gain or lose electrons.

Uses:

• Helium is used to fill air-ships and ballons. Because of its low solubility it is also used in breathing mixtures for deep-sea diving. Liquid helium is used to pressurise the liquid hydrogen fuel in rockets.

• Argon’s main use is in the steel industry where it is blown into furnaces to stir the molten metal and is used in ’argon plasma torches’ to prevent dangerous metal dusts escaping into the environment.

• Argon is used in welding as a shielding gas to provide protection against oxidation.

• Lasers, like the ones used in supermarket bar-code readers are filled with neon or a neon/helium mixture

• Krypton lasers are a vital tool in eye surgery, where the intense beam is used to prevent retinal bleeding

• Xenon is used to make special lasers which produce ultraviolet light in high energy pulses. These are used to cut high-tech materials which are so hard they cannot even be cut with diamonds

• The mass spectrometer, an indispensable research tool, depends on xenon for its calibration

• Xenon is used in Computerised Axial Tomography (CAT) scanners, the most advanced medical X-ray machines yet developed

• High-energy fluorescent lighting tubes contain a mixture of argon and krypton

• High-powered bulbs used in lighthouses are filled with argon and krypton

• The flashes in cameras rely on xenon

Physical Properties:

Symbol He Ne Kr Xe Ar

Atomic number 2 10 36 54 18

Relative atomic mass 4 20 83 131 34

Boiling point 4 K 27 K 121 K 165 K 87 K

Key properties • Unreactive

• Insoluble

• ‘Leaky’

• Cold

• Light • Odourless

• Colourless

• All produce light when an electric current is applied • Unreactive

Discoverers Pierre Janssen (1868) William Ramsey (1898)

Major industrial applications • Balloons

• Airships

• Diving

• Leak detection

• Superconductors • Lighting

• Advertising

• Lasers

• CAT scanners

• Superconductors • Steel production

• Welding

• Lighting

Name: Helium

Symbol: He

Atomic Number: 2

Atomic Mass: 4.002602 amu

Melting Point: -272.0 °C (1.15 K, -457.6 °F)

Boiling Point: -268.6 °C (4.549994 K, -451.48 °F)

Number of Protons/Electrons: 2

Number of Neutrons: 2

Classification: Noble Gas

Crystal Structure: Hexagonal

Density @ 293 K: 0.1785 g/cm3

Color: colorless

Atomic Structure

Number of Energy Levels: 1

First Energy Level: 2

Isotopes

Isotope Half Life

He-3 Stable

He-4 Stable

Facts

Date of Discovery: 1895

Discoverer: Sir William Ramsey

Name Origin: From the Greek word hêlios (sun)

Uses: balloons, deep sea diving

Obtained From: natural gas deposit, air

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/cm3

Color: colorless

Atomic Structure

Number of Energy Levels: 2

First Energy Level: 2

Second Energy Level: 8

Isotopes

Isotope Half Life

Ne-20 Stable

Ne-21 Stable

Ne-22 Stable

Facts

Date of Discovery: 1898

Discoverer: Sir William Ramsey

Name Origin: Form the Greek word neos (new)

Uses: lighting

Obtained From: liquid air

Name: Argon

Symbol: Ar

Atomic Number: 18

Atomic Mass: 39.948 amu

Melting Point: -189.3 °C (83.85 K, -308.74 °F)

Boiling Point: -186.0 °C (87.15 K, -302.8 °F)

Number of Protons/Electrons: 18

Number of Neutrons: 22

Classification: Noble Gas

Crystal Structure: Cubic

Density @ 293 K: 1.784 g/cm3

Color: Colorless Gas

Atomic Structure

Number of Energy Levels: 3

First Energy Level: 2

Second Energy Level: 8

Third Energy Level: 8

Isotopes

Isotope Half Life

Ar-36 Stable

Ar-37 35.0 days

Ar-38 Stable

Ar-39 269.0 years

Ar-40 Stable

Ar-41 1.8 hours

Facts

Date of Discovery: 1894

Discoverer: Sir William Ramsey

Name Origin: From the Greek word argon (inactive)

Uses: Lighting

Obtained From: air

Name: Krypton

Symbol: Kr

Atomic Number: 36

Atomic Mass: 83.8 amu

Melting Point: -157.2 °C (115.950005 K, -250.95999 °F)

Boiling Point: -153.4 °C (119.75001 K, -244.12 °F)

Number of Protons/Electrons: 36

Number of Neutrons: 48

Classification: Noble Gas

Crystal Structure: Cubic

Density @ 293 K: 3.74 g/cm3

Color: colorless gas

Atomic Structure

Number of Energy Levels: 4

First Energy Level: 2

Second Energy Level: 8

Third Energy Level: 18

Fourth Energy Level: 8

Isotopes

Isotope Half Life

Kr-78 Stable

Kr-79 1.45 days

Kr-80 Stable

Kr-81 210000.0 years

Kr-82 Stable

Kr-83 Stable

Kr-83m 1.86 hours

Kr-84 Stable

Kr-85 10.73 years

Kr-85m 4.48 hours

Kr-86 Stable

Kr-87 1.27 hours

Kr-88 2.84 hours

Kr-89 3.15 minutes

Kr-90 32.3 seconds

Facts

Date of Discovery: 1898

Discoverer: Sir William Ramsey

Name Origin: From the Greek word kryptos (hidden)

Uses: Lighting

Obtained From: production of liquid air

Name: Xenon

Symbol: Xe

Atomic Number: 54

Atomic Mass: 131.29 amu

Melting Point: -111.9 °C (161.25 K, -169.42 °F)

Boiling Point: -108.1 °C (165.05 K, -162.58 °F)

Number of Protons/Electrons: 54

Number of Neutrons: 77

Classification: Noble Gas

Crystal Structure: Cubic

Density @ 293 K: 5.8971 g/cm3

Color: Colorless Gas

Atomic Structure

Number of Energy Levels: 5

First Energy Level: 2

Second Energy Level: 8

Third Energy Level: 18

Fourth Energy Level: 18

Fifth Energy Level: 8

Isotopes

Isotope Half Life

Xe-122 20.1 hours

Xe-123 2.0 hours

Xe-124 Stable

Xe-125 17.1 hours

Xe-126 Stable

Xe-127 36.41 days

Xe-128 Stable

Xe-129 Stable

Xe-129m 8.89 days

Xe-130 Stable

Xe-131 Stable

Xe-131m 4.9 days

Xe-132 Stable

Xe-133 5.24 days

Xe-133m 2.19 days

Xe-134 Stable

Xe-135 9.1 hours

Xe-135m 15.36 minutes

Xe-136 Stable

Xe-137 3.82 minutes

Xe-138 14.13 minutes

Facts

Date of Discovery: 1898

Discoverer: Sir William Ramsay

Name Origin: From the Greek word xenon (stranger)

Uses: powerful lamps, bubble chambers

Obtained From: liquid air

Name: Radon

Symbol: Rn

Atomic Number: 86

Atomic Mass: (222.0) amu

Melting Point: -71.0 °C (202.15 K, -95.8 °F)

Boiling Point: -61.8 °C (211.35 K, -79.24 °F)

Number of Protons/Electrons: 86

Number of Neutrons: 136

Classification: Noble Gas

Crystal Structure: Cubic

Density @ 293 K: 9.73 g/cm3

Color: colorless

Atomic Structure

Number of Energy Levels: 6

First Energy Level: 2

Second Energy Level: 8

Third Energy Level: 18

Fourth Energy Level: 32

Fifth Energy Level: 18

Sixth Energy Level: 8

Isotopes

Isotope Half Life

Rn-211 14.6 hours

Rn-212 24.0 minutes

Rn-217 0.6 milliseconds

Rn-218 35.0 milliseconds

Rn-219 3.96 seconds

Rn-220 55.61 seconds

Rn-222 3.82 days

Facts

Date of Discovery: 1898

Discoverer: Fredrich Ernst Dorn

Name Origin: From radium

Uses: treatment of cancer

Obtained From: decay of radium