اطلاعات پایه ای در مورد عناصر گروه هشتم اصلی

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 Ramsay
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 Ramsay
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 Ramsay
Name Origin: From the Greek word argon (inactive)
Uses: Lighting
Obtained From: 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