Answer:
Physical property: Any characteristic that can be determined without changing the substance's chemical identity. Chemical property: Any characteristic that can be determined only by changing a substance's molecular structure.
Explanation:
Physical properties are something that is reverseable or has no change visible. Chemical properties are something that is NOT reverseable.
Chemical: Gas forming or Color Changing. (ETC.)
(2) U-238 is the radioisotope used in dating geological formations. Uranium-238 has a half-life of 4.46 billion years, which makes it suitable to date such old formations.
The other options do not have such long durabilities and half-lives.
Answer/Explanation: Two atoms of oxygen form the basic oxygen molecule--the oxygen we breathe that is essential to life. The third oxygen atom can detach from the ozone molecule, and re-attach to molecules of other substances, thereby altering their chemical composition.
In order to form new molecules, a chemical reaction would have to occur which means the change would be a chemical change.