Explanation:
1) Initial mass of the Cesium-137=
= 180 mg
Mass of Cesium after time t = N
Formula used :
Half life of the cesium-137 =
= initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope
= rate constant

Now put all the given values in this formula, we get
Mass that remains after t years.

Therefore, the parent isotope remain after one half life will be, 100 grams.
2)
t = 70 years


N = 35.73 mg
35.73 mg of cesium-137 will remain after 70 years.
3)


N = 1 mg
t = ?

t = 224.80 years ≈ 225 years
After 225 years only 1 mg of cesium-137 will remain.
Answer: I believe it is critical mass
Explanation:
Answer:the answer is b
Explanation:I took the test and got it right
Answer:
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Explanation:
Gold does not tarnish, rust or corrode. Due to its wonderful qualities and its luster, gold is considered the most important metal in jewellery making. As pure gold is too soft for everyday wear, it is alloyed with a mixture of metals in order to make the gold harder, so it can be used for jewellery.
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Answer:
c
Explanation:
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