Oxygen-16 and Carbon-12 are stableisotopes of elements O and C respectively. Hence, they do not have half-lives. But Carbon-14 andUranium-238 are radioactive isotopes. Among them Carbon-14 has relatively short half-life as about 5730 years while Uranium-238 has a long half-life as about 4.5 billion years.
Answer is. uranium-238
<span>While modern fiberglass has no increased risk of mesothelioma, there is a risk of removing older insulation that may have had asbestos, a known cancer causing agent, especially in cases of mesothelioma.</span>
Answer: C). Extraction
Explanation:
Minerals are the inorganic susbtances obtain from the under surface of the earth crust. They are collectively found in the geosphere of earth.
The mineral formation is a long geomorphic process it does not involve any biological activity. After mineral formation mineral extraction is the next step in the resource cycle.
The extraction process involves mining techniques.
Answer: The immune system
Explanation:
The immune system is a complex network of proteins and cells that defends the body against infection or any invasion. The human defense system in the body is actually made up of entire organs and vessel systems like the lymph vessels. The immune system is made up of organs that control the production and maturation of certain defense cells.
Initially, all living things are subjected to attack from disease causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.
