Answer:

Explanation:
A radioactive isotope is an isotope that undergoes nuclear decay, breaking apart into a smaller nucleus and emitting radiation during the process.
The half-life of an isotope is the amount of time it takes for a certain quantity of a radioactive isotope to halve.
For a radioactive isotope, the amount of substance left after a certain time t is:
(1)
where
is the mass of the substance at time t = 0
m(t) is the mass of the substance at time t
is the half-life of the isotope
In this problem, the isotope is uranium-235, which has a half-life of

We also know that the amount of uranium left in the rock sample is 6.25% of its original value, this means that

Substituting into (1) and solving for t, we can find how much time has passed:

Answer:
So, I don't know if this is 100% correct, but, I believe it's <u><em>B.photosynthetic organisms to herbivores to carnivores and decomposers.</em></u> I'm so sorry if it's wrong!
Explanation: looked all over go ogle.
Have a good morning, afternoon, or night!
<em>~</em><u><em>Dreamer1331</em></u><em>~</em>
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<em>*please mark brainliest when possible, if correct, and if you feel I deserve it, Thank you!*</em>
Answer:
A. 140,800 J
Explanation:
Specific heat of a material is defined as the amount of energy required to increase in 1°C 1kg of the material. <em>For wood there are required 1760J perkg per °C.</em>
The equation is:
Q = C*m*ΔT
<em>Where Q is heat in Joules,</em>
<em>C is specific heat (1760J/kg°C),</em>
<em>m is mass (2kg)</em>
<em>ΔT is change in temperature (50°C - 10°C = 40°C)</em>
Replacing:
Q = 1760J/kg°C*2kg*40°C
Q = 140800J
Right option is:
<h3>A. 140,800 J
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