Atomic number: 1
Symbol: H
Category: non-metal
Density at 25°C: gas
Hydrogen is the first element. It is perhaps the most basic element of matter that can take place in a chemical reaction. It consists of a proton and optional neutron and an electron.
A discharge tube, an electrically excited sample of hydrogen. image:wikipedia
H by itself is still quite unstable and almost always naturally bound with another H atom to form H2 ( called a diatomic molecule)
Sometimes it was left by itself on the periodic table, now it sits on the top left because it tends to react rather like a reactive metal, just below it, that reactive element is lithium.
Use, natural applications or common combinations:
- stars and nebula, gas giant planets
- bound with oxygen to produce water, H2O
Basic characteristics:
- Standard atomic weight: 1.008
- Melting/freezing point: -259.14 °C
- Boiling point: -252.87 °C
- Radioactivity:
- isotopes: 3H half life: 12.32 years via beta - decay emitting an electron.