Answer:

Explanation:
The mass of radioactive isotope at a certain time is given by the following expression:

Time constant can be calculed in terms of half-life:



The initial mass is:


C was the answer i had and it was right
Answer:
# In a familiar high-school chemistry demonstration, an instructor first uses electricity to split water into its constituent gases, Hydrogen and Oxygen. Then, by combining the two gases and igniting them with a spark, the instructor changes the gases back into water with a loud pop (That means the energy is released in the process).
# There are new other ways to produce water in laboratory, however, the scientists can not produce water in large quantity for the masses, because of some reasons.
1- Theoretically, this is possible, but it would be an extremely dangerous process. Since Hydrogen is extremely flammable and Oxygen supports combustion, it wouldn’t take much to create this force, but we also have an explosion. That’s why this process can be a deadly one if our experiment is big enough.
2- Personally, I think that it makes no sense to produce water in a laboratory ( or in a large plant) for people to use as daily water. The much more important thing we need to do is to save our environment, our planet Earth. Because the daily water people drink contains not just water molecules but other minerals, the marine life is depend not just in water molecules but diferent factors, etc.
Explanation:
This is just my personal opinion. Hope that can help you a little. Have a nice day
Ammonia is formed by a reaction between hydrogen and nitrogen as shown by the equation below.
N2(g) + 3H2(g) = 2NH3(g)
1 mole of ammonia contains 17 g
Therefore 10.78 g of ammonia are equivalent to 10.78/17 = 0.6341 moles
The mole ratio of hydrogen to ammonia is 3 : 2
Therefore, moles of hydrogen used will be 0.6341 × 3/2 = 0.9512 moles
1 mole of hydrogen is equivalent to 2 g
Thus, the mas of hydrogen will be 0.9512 moles × 2 = 1.9023 g