Answer: It reacts vigorously with oxygen to form water.
Step-by-step explanation:
Physical property is defined as the property of a substance which becomes evident during physical changes.
Example: At room temperature its density is less than any other gas.
Liquefied
boils at a very low temperature

Chemical property is defined as the property of a substance which becomes evident during chemical changes. These properties are defined when a substance undergo changes in bonding of atoms.
Example: It reacts vigorously with oxygen to form water.