Krypton is an unreactive gas.
Uses and research
It is used in some lamps and specialized light sources.
A family that reacts reluctantly
The noble gases occupy the right-hand column. The familiar members react reluctantly, but this does not mean that compounds are impossible: some heavier noble gases form compounds. Membership of a group is a clue, not a guarantee of every property. Oganesson has not been observed as an ordinary bulk gas.
What the atomic number tells us
Krypton has atomic number 36. This is the number of protons in its nucleus. A neutral atom also has 36 electrons. Losing or gaining electrons makes an ion; it does not change the element unless the proton count changes.
The model's rings help count electrons by shell. They are not actual circular paths. A model of one atom and the properties of a whole material are different levels of description.
Temperature and state
25°C: Gas
Illustrative particle motion: sizes, distances and speeds are not to scale. Particles represent atoms or molecules.
← CoolHeat →
Melting point -157.36°C / Boiling point -153.22°C
Pure element at 1 atmosphere. Image conditions are explained in captions. Pictures do not change with temperature.