A catalyst is a substance that increases the rate of a chemical reaction without itself being consumed . (ans: second choice)
Answer:
Radium-226 is a radioactive decay product in the uranium-238 decay series and is the precursor of radon-222. Radium-228 is a radioactive decay product in the thorium-232 decay series. Both isotopes give rise to many additional short-lived radionuclides, resulting in a wide spectrum of alpha, beta and gamma radiations.
It would help if I could see the specific answer choices, but an environment that would have lots of oxygen, water, decaying organisms and sunlight would be the answer (ex. the forest or riverbed)
Option C: elements produce spectra with only few distinct lines.
The spectra are not continuos and are different for every element. This permits to identify elements.
