Not known
Yes.
a Chemical Property
flamability
chemical
That is a chemical property. A physical property could be its mass, volume, density, physical state, or that it can tear easily. A physical property is one that does not change the chemical composition of the substance.
something that catches on fire.
chemical
Flammability is considered a chemical property because it involves how a substance will react with oxygen in a combustion reaction to produce heat and light. It is related to the chemical structure and composition of the material.
physical
Astatine is an element with the symbol At.
It readily catches fire when exposed to oxygen.
Astatine has 125 neutrons