<h2>
Answer: The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.</h2>
Explanation:
The half-life 
of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this case, we are given the half life of two elements:
beryllium-13: 
beryllium-15: 
As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?
We can find it out by the following expression:
Where 
is the amount we want to find:
Finally:
Therefore:
The half-life of beryllium-15 is <u>400 times greater than</u> the half-life of beryllium-13.
The reasoning which is in use when large, angular rocks are interpreted to have originated from the outcrop at the top of the hill is; Fossil succession
<h3>Fossil succession of rocks</h3>
The principle of fossil succession in characterized by the fact that fossil entities succeed one another upward through rock layers in a definite and determinable order.
On this note, any time period can be dated by its fossil content.
Read more on fossil succession;
brainly.com/question/2631497
Coal is burned to get energy. By burning coal, green houses gases like carbon dioxide, nitrogen oxides and suphur oxides are produced.
Rest of the energy sources given in the option are clean energies.
Answer is A.
I believe the correct answer from the choices listed above is the third option. <span>The force exerted by the book on the table is equal to the force exerted by the table which is 4.0 N. The book does not move so it must be that the forces are balanced. Hope this answers the question.</span>
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Answer:
1. The magnitude of the force from the spring on the object is zero on <em>Equilibrium.</em>
2. The magnitude of the force from the spring on the object is a maximum on <em>The top and bottom.</em>
3. The magnitude of the net force on the object is zero on <em>The Bottom.</em>
4. The magnitude of the force on the object is a maximum on <em>the Top.</em>
Explanation:
<em>1. Because the change in position delta X is zero.</em>
<em>2. Because of delta X.</em>
<em>3. Beacuse, the force of gravity and the force of the spring oppose each other to keep the block at rest, away from the equilibrium position.</em>
<em>4. Because, the force of the spring from compressiom and the force of gravity both act on the mass.</em>
