Answer:
Explanation:
Helium is the second most abundant element in the universe, but here on earth, it's rather rare. Most people guess that we extract helium from the air, but actually we dig it out of the ground. Helium can be found in certain parts of the world, notably in Texas, as a minor component in some sources of natural gas.
Helium is generated underground by the radioactive decay of heavy elements such as uranium and thorium. Part of the radiation from these elements consists of alpha particles, which form the nuclei of helium atoms. ... Helium can also be produced by liquefying air and separating the component gases
When the gas contains more than about 0.4% helium by volume, a cryogenic distillation method is often used in order to recover the helium content. Once the helium has been separated from the natural gas, it undergoes further refining to bring it to 99.99+% purity for commercial use.
Answer:
B
Explanation:
expands and cools water vapor condenses and clouds develop
Yes, all ecosystems need to have a top predator (quaternary consumers) so that the cycle of the food chain can stay complete.
C. Microscope
They were able to get magnification like never before
Answer:
positive feedback
Explanation:
Negative feedback makes the body back to normal, for example, the body releases less glucose into the blood when there is a high blood sugar. Since more growth hormones are released because of the presence of growth hormones, this cannot be negative feedback.
Positive feedback increases a stimulus, for example, the body's release of Oxycontin during labor, causing contractions. These contractions cause more Oxycontin to be released. Since the stimuli is increasing, we can say its positive feedback
