Electromagnetic radiation is a form of energy that propagates as both electrical and magnetic waves traveling in packets of energy called photons. There is a spectrum of electromagnetic radiation with variable wavelengths and frequency, which in turn imparts different characteristics.
This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space. ...
Lead is often used to block out radiation
Potassium is a chemical element
Symbol: K
Atomic number: 19
Atomic mass: 39.0983 u ± 0.0001 u
Electron configuration: [Ar] 4s1
Melting point: 146.3°F (63.5°C)