What percent of potassium-40 remains undecayed in a rock that is 3.9 billion years old? The 3.9 billion year old rock has undergone three half-lives (3.9 divided by 1.3 = 3). After 3 half-lives, 12.5% of the potassium-40 remains undecayed.
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<h3>⭐What does polar mean? </h3>
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- D. An unequal sharing of electrons
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<em><u>Chemical polarity or only polar is a property of molecules that represents the separation of electric charges in the same molecule (see also electric dipole). ...</u></em>
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atte:
<u>Angela</u>
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Answer:
Two populations of birds live in the same area but have different sleep/wake cycles this is Chronotype.
Explanation:
Every organism has a biological clock called Circadian rhythm. Circadian rhythm is a cycle of 24 hours and determine the particular activities within these 24 hours for example sleep and wake cycle. Whereas a chronotype is a natural tendency of any organism toward sleep preference within their circadian rhythm. for example, owl prefers to stay active during night while sparrow sleeps at night.
Answer:
Environment.
Explanation:
The respiratory system interacts with the environment by contracting and expanding the diaphragm and chest in order to do breathing. When the muscles in the diaphragm contracts and the expansion of chest occurs, takes the air inside the body that is present in the outside environment for inhalation of oxygen while on the other hand, when the diaphragm expands and chest contract, the air inside the body is removed with the removal of carbondioxide gas.
