Animals use the respiratory system to breathe in oxygen and other gases and expel gases like CO2, right? O2 in, CO2 out.
Answer:
Swishing sound.
Explanation:
Human heart produces unique sound when blood flows from one chamber to the next chamber. The two main sounds produced by heart are lub abd dub sound.
The doctor's examine the Janetta's heart and told that she has incompetent right atrioventricular valve. The doctor must have heard the swishing sound after the closing of right atrioventricular valve. This sound is the direct indication of incompetent AV valve.
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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Answer:
Because igneous Rock is separated into different minerals. Radio carbon dating works by measuring the amount of carbon dioxide.