
Helium (He) is a chemical element of the periodic table, located in the group 18 and the period 1, and is having the atomic number 2. It is a colorless, odorless, tasteless, non-toxic gas, whose name comes from the Greek word “helios”, which means sun. It is the first element in the noble gas group. It is the second lightest element, after the hydrogen element.
1 |
2 |
||||||||||||||||||
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
||||||||||||
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
||||||||||||
19 |
20 |
21 |
22 |
23 |
24 |
25 |
26 |
27 |
28 |
29 |
30 |
31 |
32 |
33 |
34 |
35 |
36 |
||
37 |
38 |
39 |
40 |
41 |
42 |
43 |
44 |
45 |
46 |
47 |
48 |
49 |
50 |
51 |
52 |
53 |
54 |
||
55 |
56 |
72 |
73 |
74 |
75 |
76 |
77 |
78 |
79 |
80 |
81 |
82 |
83 |
84 |
85 |
86 |
|||
87 |
88 |
104 |
105 |
106 |
107 |
108 |
109 |
110 |
111 |
112 |
113 |
114 |
115 |
116 |
117 |
118 |
|||
57 |
58 |
59 |
60 |
61 |
62 |
63 |
64 |
65 |
66 |
67 |
68 |
69 |
70 |
71 |
|||||
89 |
90 |
91 |
92 |
93 |
94 |
95 |
96 |
97 |
98 |
99 |
100 |
101 |
102 |
103 |
– s block |
FAQs on Helium Element
Helium |
---|
‣ What does helium look like? Appearance: colorless gas, exhibiting a gray cloudy glow (or reddish-orange if an especially high voltage is used) when placed in an electric field |
‣ When was helium discovered and by whom? Discovery: Pierre Janssen Norman Lockyer (1868) First isolation: William Ramsay, Per Teodor Cleve, Abraham Langlet (1895) |
‣ Where is helium located on the periodic table?![]() Location: Helium is found in the eighteenth column of the periodic table above the neon element. |
‣ What is helium’s atomic number? Atomic number (Z): 2 |
‣ What is the correct symbol for helium? Symbol: He |
‣ What is the atomic weight of helium? Standard atomic weight: 4.002602 |
‣ Helium belongs to which block? Block: s-block |
‣ What group is helium in on the periodic table? Group: 18 (noble gases) |
‣ What period is helium in on the periodic table? Period: 1 |
‣ Helium covalent radius: 28 pm |
‣ Helium Van der Waals radius: 140 pm |
‣ What is helium’s melting point? Melting point: 0.95 K (-272.20 °C, -457.96 °F) (at 2.5 MPa) |
‣ What’s the boiling point of helium? Boiling point: 4.222 K (-268.928 °C, -452.070 °F) |
‣ Helium critical point: 5.1953 K, 0.22746 MPa |
‣ Helium triple point: 2.177 K, 5.043 kPa |
‣ How many electron shells does helium have? Electrons per shell: 2 |
‣ What is helium’s electron configuration? Electron configuration: 1s2 |
‣ What is helium ionization energy? Ionization energies: 1st: 2372.3 kJ/mol 2nd: 5250.5 kJ/mol |
‣ In what phase is helium normally found? Phase (at r.t): gas |
‣ What is the density of helium at STP? Density (at STP): 0.1786 g/L when liquid (at m.p): 0.145 g/cm3 when liquid (at b.p): 0.125 g/cm3 |
‣ Helium magnetic ordering: diamagnetic |
‣ Helium natural occurrence: primordial |
‣ Helium oxidation state: 0 |
‣ What is helium electronegativity? Electronegativity: Pauling scale: no data |
‣ Helium heat of fusion: 0.0138 kJ/mol |
‣ Helium heat of vaporization: 0.0829 kJ/mol |
‣ Helium molar heat capacity: 20.78 J/(mol K) |
‣ Helium molar magnetic susceptibility: -1.88 × 10-6 cm3/mol (298 K) |
‣ Speed of sound in helium: 972 m/s |
‣ What is the crystal structure of helium? Crystal structure: hexagonal close-packed (hcp) |
‣ Thermal conductivity of helium: 0.1513 W/(m.K) |
‣ Helium CAS number: 7440-59-7 |
‣ Helium vapor pressure
Vapor pressure (defined by ITS-90) | ||||||
---|---|---|---|---|---|---|
P (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
at T (K) | 1.23 | 1.67 | 2.48 | 4.21 |
‣ How many isotopes does helium have?
Main isotopes of helium | ||||
---|---|---|---|---|
Isotope | Abundance | Half-life (t1/2) | Decay mode | Product |
3He | 0.0002 % | stable | ||
4He | 99.9998 % | stable |
.
.
.
Related:
Also Read:
- Hydrogen
- Lithium
- Beryllium
- Boron
- Carbon
- Nitrogen
- Oxygen
- Fluorine
- Neon
- Sodium
- Magnesium
- Aluminium
- Silicon
- Phosphorus
- Sulfur
- Chlorine
- Argon
- Potassium
- Calcium
- Scandium
- Titanium
- Vanadium
- Chromium
- Manganese
- Iron
- Cobalt
- Nickel
- Copper
- Zinc
- Gallium
- Germanium
- Arsenic
- Selenium
- Bromine
- Krypton
- Rubidium
- Strontium
- Yttrium
- Zirconium
- Niobium
- Molybdenum
- Technetium
- Ruthenium
- Rhodium
- Palladium
- Silver
- Cadmium
- Indium
- Tin
- Antimony
- Tellurium
- Iodine
- Xenon
- Caesium
- Barium
- Lanthanum
- Cerium
- Praseodymium
- Neodymium
- Promethium
- Samarium
- Europium
- Gadolinium
- Terbium
- Dysprosium
- Holmium
- Erbium
- Thulium
- Ytterbium
- Lutetium
- Hafnium
- Tantalum
- Tungsten
- Rhenium
- Osmium
- Iridium
- Platinum
- Gold
- Mercury
- Thallium
- Lead
- Bismuth
- Polonium
- Astatine
- Radon
- Francium
- Radium
- Actinium
- Thorium
- Protactinium
- Uranium
- Neptunium
- Plutonium
- Americium
- Curium
- Berkelium
- Californium
- Einsteinium
- Fermium
- Mendelevium
- Nobelium
- Lawrencium
- Rutherfordium
- Dubnium
- Seaborgium
- Bohrium
- Hassium
- Meitnerium
- Darmstadtium
- Roentgenium
- Copernicium
- Nihonium
- Flerovium
- Moscovium
- Livermorium
- Tennessine
- Oganesson