Yes. A radioactive standard is a configuration of radioactive material constructed in a precise way, allowing the standard to be used as a reference when measuring other radiation sources. Standards...
It depends. There are over 20 isotopes (types) of copper. Most of them are radioactive, but also quite rare. So any copper an average person would see would not be radioactive.
Yes. A radioactive atom is a radioactive atom. If that atom exists as a single atom and is uncombined and it is radioactive, it's radioactive. If that same atom is chemically combined with another or...