The original mass of krypton 81 that is present in the ice is 6.70 grams.
<h3>How do we calculate original mass?</h3>
Original mass of any substance will be calculated as below for the decomposition reaction is:
N = N₀(1/2)ⁿ, where
N = remaining mass of krypton-81 = 1.675g
N₀ = original mass of krypton-81 = ?
n will be calculated as:
n = T/t, where
T = total time period = 458,000 years
t = half life time = 229,000 years
n = 458,000/229,000 = 2
Now putting all these values on the above equation, we get
N₀ = 1.675 / (1/2)²
N₀ = 6.70 g
Hence required mass is 6.70 g.
To know more about half life time, visit the below link:
brainly.com/question/2320811
Answer:
The total energy of the system is maintained as energy is transformed.
Explanation:
The total energy of the system is conserved.
Answer:
The concentration is 6.42×10^-4 M
Explanation:
Number of moles trichloroethylene = pressure × volume/Henry's constant = 0.00301×0.21/0.00985 = 0.0642 mol
Volume of mixture = 100 L
Concentration of trichloroethylene = number of moles of trichloroethylene/volume of solution = 0.0642/100 = 6.42×10^-4 M
Just count the number C’s and H’s
Explanation:
a) Bohr model is perfect for atoms that have single electron and fortunately both Be3+ ion and H atom have one electron so, Bohr model can easily and accurately applied to predict the spectrum of Be3+ and H atom.
b) The energy of an atom in Bohr model is given by

the values of z for H atom and Be3+ ion are 1 and 4 respectively. Hence, energy of atoms would be different for both atoms. Hence, line spectra to be identical is not possible.