highly reactive with alkali metals and alkaline earth metals
Molecules in the vapours are diatomic. All the molecules in the vapour are non-polar.
low boiling point and high reactivity
The most common halogen on the periodic table would have to be either chlorine or iodine.
Iodine
low boiling point and high reactivity
Iodine
This hypothetical halogen will have the atomic number 133, will be solid, dense and extremely unstable.
Iodine
Iodine
Halogen refrigerants are also known as coolant chemicals, which can cause ozone damage. A great example of a common halogen refrigerant would be Freon.
Chlorine in domestic instance and flourine in atmosphere.
Astatine is a heavy halogen; no similarities with strontium (alkaline earth metal).