A radioactive nucleus has a half-life of 4.5 × 10 8 years. Assuming that a sample of rock (say, in an asteroid) solidified right after the solar system formed, approximately what fraction of the radioactive element should be left in the rock today?

Explanation:

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answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.

a. population growth is decreasing

-2

+4

-10

-3

-8

-3

so the population decreased by 24 because 3+3+8+10+2=26-2=24.

hoped i !

explanation: