<u>Answer:</u> The half life of the given radioactive isotope is 43.86 minutes
<u>Explanation:</u>
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken for decay process = 233 minutes
= initial amount of the reactant = 0.500 M
[A] = amount left after decay process = 0.0125 M
Putting values in above equation, we get:

The equation used to calculate half life for first order kinetics:

where,
= half-life of the reaction = ?
k = rate constant = 
Putting values in above equation, we get:

Hence, the half life of the given radioactive isotope is 43.86 minutes
The continental crust is the layer of granitic, sedimentary and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves. It is less dense than the material of the Earth's mantle and thus "floats" on top of it.
<span>d. flourine </span> fluorine<span> is the most reactive halogen
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Your first step is determining how many gram of KCl are in every mole of KCl. This can be done by simply looking at K and Cl's atomic mass on the Periodic Table. You add K's atomic mass (39.1g) with Cl's atomic mass (35.45g) to determine that the mass of one mole of KCl is 74.55g. Because you have 10 moles of KCl you multiply 74.55g by 10 to reach your answer of 745.5g.