Gravity and friction inhibit the motion of the object, respectively
<h3>
Answer:</h3>
20 g
<h3>
Explanation:</h3>
We are given;
Original mass of K-40 before decay = 80 g
Half life of Potassium-40 = 1.25 billion years
Time taken by the decay = 2.5 billion years
We are required to calculate the mass of K-10 that will remain after 2.5 billion years.
Using the formula;
Remaining mass = Original mass × (1/2)^n
where n is the number of half lives
Number of half lives, n = Time taken ÷ half-life
= 2.5 billion years ÷ 1.25 billion years
= 2
Remaining mass = 80 g × (0.5)^2
= 80 g × 0.25
= 20 g
Therefore, the mass of K-40 isotope that will remain after 2.5 billion years is 20 g.
The question is incomplete, the complete question is:
A chemist measures the amount of iodine solid produced during an experiment. He finds that 8.31 g of iodine solid is produced. Calculate the number of moles of iodine solid produced. Round your answer to the correct number of significant digits.
<u>Answer: </u>The number of moles of solid iodine produced is 0.0327 moles
<u>Explanation:</u>
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
......(1)
Given mass of solid iodine = 8.31 g
Molar mass of solid iodine = 253.8089 g/mol
Plugging values in equation 1:
Hence, the number of moles of solid iodine produced is 0.0327 moles
C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O
I think that the answer is d