0.25 g of U-235 isotope will be left.
<h3><u>
Formula used :</u></h3>
N = N₀/2
where,
N = amount of U-235 left after n-half lives = ?
N₀ = Initial amount of the U-235 = 1.00 g
n = number of half lives passed = 2ⁿ
Using the formula, we can conclude:
N = 1/2² = 0.25
Thus, 0.25 g of U-235 isotope will left .
<h3><u>The concept of half lives</u></h3>
A half-life is the amount of time it takes for something to go from 100% to 50%. The phrase is most frequently used in reference to radioactive decay, which happens when energetic atomic particles that are unstable lose momentum. There are 29 elements that have been shown to be capable of going through this process.
Like pharmaceuticals, advertising campaigns, and a variety of other things, information likewise has a half-life.
To view more questions based on half lives, refer to:
brainly.com/question/27144626
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Answer:
Kb![= 1.58 * 10^{-6}](https://tex.z-dn.net/?f=%3D%201.58%20%2A%2010%5E%7B-6%7D)
Explanation:
The correct question is
What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?
Solution-
N2H4Cl hydrolyses on addition of water
The reaction equation is as follows -
N2H4+ + H2O ----> N2H4 + H3O+
![Ka = \frac{K_w}{K_b} = \frac{10^{-14}}{K_b}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7BK_w%7D%7BK_b%7D%20%3D%20%5Cfrac%7B10%5E%7B-14%7D%7D%7BK_b%7D)
pH
![[H+] = 10^{-pH} = 10^{-4.5}](https://tex.z-dn.net/?f=%5BH%2B%5D%20%3D%2010%5E%7B-pH%7D%20%3D%2010%5E%7B-4.5%7D)
![K_b= \frac{10^{-14} }{K_b} = \frac{Y_2}{0.158} \\K_b= \frac{(10^{-4.5})^2}{0.158}\\=> Kb = 0.158 * 10-14 /(10-4.5)2](https://tex.z-dn.net/?f=K_b%3D%20%20%5Cfrac%7B10%5E%7B-14%7D%20%7D%7BK_b%7D%20%3D%20%20%5Cfrac%7BY_2%7D%7B0.158%7D%20%20%5C%5CK_b%3D%20%5Cfrac%7B%2810%5E%7B-4.5%7D%29%5E2%7D%7B0.158%7D%5C%5C%3D%3E%20Kb%20%3D%200.158%20%2A%2010-14%20%2F%2810-4.5%292)
Kb![= 1.58 * 10^{-6}](https://tex.z-dn.net/?f=%3D%201.58%20%2A%2010%5E%7B-6%7D)
The Earth is divided into three chemical layers: the Core [Inner Core (D) and Outer Core (C)], the Mantle (B) and the Crust (A). The Core is predominantly composed of iron and nickel. Even after 4.5 billion years of cooling, the Earth's core remains very hot.