Helium

 The chemical element He is Helium. 🎈

Here is some essential information about it:

 * Symbol: He

 * Atomic Number: 2

 * Atomic Mass: \approx 4.003 u

 * Classification: Noble Gas (Group 18), the second-lightest element.

 * State at Standard Temperature and Pressure (STP): Colorless, odorless, tasteless gas.

Helium is the only element that cannot be solidified at normal atmospheric pressure, even at absolute zero. It is extremely unreactive (inert) and is primarily used for:

 * Lifting: Filling balloons and airships due to its low density.

 * Cryogenics: Cooling superconducting magnets in MRI machines and large research experiments, as it has the lowest boiling point of any element (\approx 4.2 K or -269^\circ\text{C}).