Helium

| Main Article
| Discussion
| Related Articles  [?]
| Bibliography  [?]
| External Links  [?]
| Citable Version  [?]
| Video [?]
| Properties [?]
| Isotopes [?]

|
|
|
|
|
|
|
|
|
|
|

This editable Main Article is under development and subject to a disclaimer.

[edit intro]

| Helium | 4.002602(2) |

|

| He

1s2 |
[ ? ] | Noble gas:

|

|
|

Properties:
Inert, colorless, odorless, non-toxic, non-flammable gas
Uses:
Cryogenics, welding, inert purging gas, scientific uses

Helium is a chemical element, typically found as a gas in its elemental form. It has the chemical symbol He, atomic number (number of protons) Z = 2, and a standard atomic weight of 4.002602 g/mol.

Helium is a monatomic noble gas. At a pressure of 101.325 kPa, it has a boiling point of -268.93 °C, and a melting point of -272.2 °C. It is of relatively low density--see Benchmark quantities.

## Isotopes[edit]

The helium atom has two stable isotopes, 3H and 4He.