The ionosphere is the part of the sun-layers which allows us to see the northern lights or auroras. The ionosphere is the most concentrated with ions and charged electrons and reflects radio waves.
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Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, although there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies with age is considered normal. Sensitivity also varies with frequency, as shown by equal-loudness contours. Routine investigation for hearing loss usually involves an audiogram which shows threshold levels relative to a normal.
Several animal species are able to hear frequencies well beyond the human hearing range. Some dolphins and bats, for example, can hear frequencies up to 100,000 Hz. Elephants can hear sounds at 14–16 Hz, while some whales can hear infrasonic sounds as low as 7 Hz (in water).
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Answer:Health
Throughout her work with radium, Marie was unaware of the effects of radioactivity exposure on the body. In her lab, she would keep tubes of radium in her pocket. [3] She began to suspect that radium negatively impacted health when one of her fellow researchers died of a blood disease, and then a few years later her personal assistant died of a blood disease. Even though she suspected that radium exposure was bad for her health, she did very little to monitor her own blood. In 1932, she broke her wrist and the break took much longer to heal than it should have. She then began to notice that her vision was deteriorating and radiation burns on her fingers were becoming more and more painful. Some days she felt too ill to even go to the lab, and finally on July 4, 1934, Marie died from aplastic anemia. [1]
Radium Exposure Treatments
Marie suspected that her health was being negatively impacted by radium exposure, but did nothing about it, most likely because there weren't any effective treatments for radium poisoning yet. At the time, scientists knew that radium was metabolized like calcium. In an attempt to remove it from the system, they manipulated calcium intake. [4] This caused little to no improvements, so parathyroid hormone was added to the treatment. Again, there was some reduction of radium, but not a significant amount. It wasn't until after Marie's death that they realized once radium is in the bones, it is extremely difficult to extract. The lack of therapies for radium exposure may explain why Marie just ignored her symptoms, because she was fully aware of her fate. [4]
© Jenna Gray. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
Explanation:
Explanation:
T=1/f
So if frequency increases the period will decrease
