shekar+and+leo+noble+gases

__**NOBLE GASES:**__
__**Introduction:**__ There are six noble gases known on the periodic table, all of these gases, helium, neon, argon, krypton, xenon and randon, none of them are reactive because its valance electrons take up the maximum number of the outer shell. As they go down the coloumn, its atomic mass gets larger and its atomic radius increases.


 * __HELIUM__**


 * 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

Helium was founded in 1868 by J. Norman, it is created from natural gas deposit. Helium is seven times lighter than air which makes things float upwards, such as balloons and blimps. This gas is slightly soluble in water and has the lowest melting point of all substances.




 * __NEON__**


 * 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

Neon was founded in 1898 by William Ramsey and M.W. Travis, it was obtained from liquid air. This gas is very commonly used for bright colorful lights, mainly used for advertising in cities. Neon lighting can be found in many colors and sometimes, different substances are added to give it a certain color.




 * __ARGON__**


 * 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

Argon was found in 1894 by William Ramsey and Rayleigh by obtaining it from the air. This gas has eight isotopes which are all stable and is used for the same uses as Neon, to make colorful advertising lights. Argon has the same solubility in water as oxygen does and its spectrum consists of red lines.



__**KRYPTON**__


 * 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

Krypton was founded in 1898 by William Ramsey and M.W.Travis by obtaining it from the production of liquid air. This colorless, odorless gas is also used for lighting such as fluorescent lighting tubes. Krypton emits bluish emission lights and has 8 stable isotopes.



Xenon was discovered by William Ramsey and M.W.Travis in 1898 by obtaining it from liquid air.This colorless, unreactive gas can be used for Xrays and also for very bright lights, especially for cars headlights. Xenon also has nine stable isotopes and this gas shows blood flow in a body.
 * __XENON__**
 * 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




 * __RANDON__**

Randon was discovered in 1900 by Fredrich Ernst Dorn, it was obtained by the decay of uranium or radium. Randon comes from the word radium and it is a very radioactive gas which can be very harmful. This cancerous gas is coloress, odorless and tasteless, it can be easily undetected unless a test is made.
 * 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