Answer:
that takes place inside a plant, producing food for the plant to survive
For radioactive materials with short half-lives, you use a very sensitive calibrated detector to measure how many counts per second it is producing. Then using the exact same set up you do the same at a latter time. You use the two readings and the time between them to determine the half-life. You don’t have to wait exactly a half-life, you can do the math with any significant time difference. Also, you don’t need to know the absolute radioactivity, as long as the set up is the same you only need to know fraction by which it changed.
For radioactive materials with long half-lives that won’t work. Instead you approach the problem differently. You precisely measure the mass of a very pure sample of the radioactive material. You can use that to calculate the number of atoms in the sample. Then you put the sample in a counter that is calibrated to determine the absolute number of disintegrations happening in a given time. Now you know how many of them are disintegrating every second. You use the following equations:
Decays per Second = (Number of Atoms) x (Decay Constant)
Half-life = (Natural Log of 2) / (Decay Constant)
And you can calculate the half-life
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D.
If the vibrations have a low frequency, the sound is heard as a __low-pitched sound_____. If the vibrations have a high frequency, then the sound is heard as a __high-pitched sound_____.
Explanation:
High pitched sound is of higher frequency because they make the air molecules vibrate much faster than low-pitched sound. Due to their high frequency, their wavelength is shorter (Remember wavelength and frequency are inversely proportional). Vice versa is true to the low-pitched sound. They vibrate air molecules slower than high-pitched sound. Their wavelength is longer and frequency smaller.
Learn More:
For mor on pitch of sound check out;
brainly.com/question/61859
brainly.com/question/1509263
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Scientists believe that the Earth's early atmosphere lacked oxygen because photosynthetic organisms did not yet exist. Hope this helps and have a great day!
Answer:
The answers are as followed:
Explanation:
9: Non renewable
10: Organisms
11: Millions
