464 g radioisotope was present when the sample was put in storage
<h3>Further explanation</h3>
Given
Sample waste of Co-60 = 14.5 g
26.5 years in storage
Required
Initial sample
Solution
General formulas used in decay:

t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
Half-life of Co-60 = 5.3 years
Input the value :

Answer:
Atomic number=No. of protons=No. of electrons in ground state(unchanged atom)
Atomic number=13=No. of protons
Atomic mass=no. of protons+no. of neutrons=13+14=27
For isotope no. of proton=13(same atomic number but different mass number are isotopes)
no. of electrons=13
no. of neutrons=14+2=16
Explanation:
hope it's help you
Answer:
B. Coal
Explanation: Coal is mined to produce energy.
Mg₃N₂ + 6H₂O = 3Mg(OH)₂ + 2NH₃
The percentage yield of the new production technique is 82.8%
<h3>What is the percentage yield?</h3>
Production is the procedure by which finished products are obtained form the raw materials. The production process involves the passing of raw materials through a certain procedure that involves the use of certain machines and equipment to give us the required products.
We are told in the question that there are three shifts;
Shift 1 produces 4562 grams
Shift 2 produces 5783 grams
Shift 3 produces 5247 grams
Average production from the three shifts = 4562 grams + 5783 grams + 5247 grams/3 = 5197 grams
The theoretical average yield is = 7000 grams + 7000 grams + 7000 grams/3 = 7000 grams
Now the percentage yield = actual yield/ theoretical yield * 100/1
percentage yield = 5197 grams/7000 grams * 100/1
percentage yield = 82.8%
Learn more about percentage yield :brainly.com/question/27492865
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