Answer:
Hello your question is poorly written below is the well written question
Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes, U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth
Answer : 140 billion years
Explanation:
Given that :
U-238 h1/2 = 4.5 billion years
U-235 h1/2 = 700 million years
At the beginning both Isotopes where present in equal amount
Determine the T years before the amount of Uranium decays to Half
T = ? N'2 = N1 / 2
we know that N = No ( 1/2 )^h where h = time / half-life time
attached below is the detailed solution of the given problem
The mole is simply an Avogadros number of anything( in this case Br atoms)
The Avogadro number is 6.022 x 10^23.
So no of moles = No of atoms / 6.022 x 10^23 = 2.03 x 10^24 / 6.022 x 10^23 = 3.37 Moles.
They have similar electron configurations and have similar ionic chargers
The reaction between <span>C3H7SH and oxygen can be illustrated using the following balanced equation:
</span>C3H7SH (l) + 6O2 (g) --> 3 CO2 (g) + SO2 (g) + 4 H2O (g)
From the balanced equation above, 6 moles of oxygen are required to produce 4 moles of water.
Therefore, to know the number of oxygen moles needed to produce 2.33 moles of water, all you have to do is cross multiplication as follows:
number of oxygen moles = (2.33*6) / 4 = 3.495 moles