Dmitri Mendeleev devised the first periodic table.
Answer:
Explanation:
Given parameters:
Number of given calories = 614 cal
Note that 1cal = 4.18J
Now to convert the given calories to joule, we use the relationship below:
Since 1Cal gives 4.18Joule of energy
614Cal will produce 4.18 x 614;
2566.52J of energy.
This written as 2.57 x 10³J because it has three significant numbers of 2, 5 and 7.
In writing an operation that involves deducing the significant numbers, we simply express our answer to that shows the lowest number of significant numbers. Our problem has 3 significant numbers each and the answer is given in that regard.
Answer: alright now listen fe203(s)=567.66666
Explanation:
The time taken for the isotope to decay is 46 million years.
We'll begin by calculating the number of half-lives that has elapsed. This can be obtained as follow:
- Original amount (N₀) = 50.25 g
- Amount remaining (N) = 16.75
- Number of half-lives (n) =?
2ⁿ = N₀ / N
2ⁿ = N₀ / N
2ⁿ = 50.25 / 16.75
2ⁿ = 3
Take the log of both side
Log 2ⁿ = 3
nLog 2 = Log 3
Divide both side by log 2
n = Log 3 / Log 2
n = 2
Finally, we shall determine the time.
- Half-life (t½) = 23 million years
- Number of half-lives (n) = 2
t = n × t½
t = 2 × 23
t = 46 million years
Learn more about half-life: brainly.com/question/25927447
