Helium (He), element 2 – Learn Acer periodic table

Noble gas, atomic number 2.

Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among all the elements.

Symbol He. Atomic mass 4.0026022 u. Group 18, period 1. Electron configuration 1s2. Electrons per shell 2. State at room temperature: Gas. Melting point -272.2 °C, boiling point -268.9 °C. Discovered by Pierre Janssen.

Element data from Wikipedia, CC BY-SA 3.0.

Helium (He), element 2 – Learn Acer periodic table

Helium

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