Answer:
2.15 mg of uranium-238 decays
Explanation:
For decay of radioactive nuclide-
where N is amount of radioactive nuclide after t time, 
is initial amount of radioactive nuclide and 
is half life of radioactive nuclide
Here 
, 
and 
So,
so, N = 2.446 mg
mass of uranium-238 decays = (4.60-2.446) mg = 2.15 mg
In group theory, a branch of mathematics, the term order is used in two unrelated senses:
<span><span>The order of a group is its cardinality, i.e., the number of elements in its set. Also, the order, sometimes period, of an element a of a group is the smallest positive integer m such that <span>am = e</span> (where e denotes the identity element of the group, and am denotes the product of m copies of a). If no such m exists, a is said to have infinite order.</span><span>The ordering relation of a partially or totally ordered group.</span></span>
This article is about the first sense of order.
The order of a group G is denoted by ord(G) or | G | and the order of an element a is denoted by ord(a) or | a |.
Answer:
"1 M" will be the right solution.
Explanation:
The given values are:
Number of moles,
= 2 moles
Volume of solution,
= 2000 mL
or,
= 2 L
Now,
The molarity of the solution will be:
= 
On substituting the values, we get
= 
= 
Answer : The time taken by the reaction is 
Explanation :
The expression used for second order kinetics is:
![kt=\frac{1}{[A_t]}-\frac{1}{[A_o]}](https://tex.z-dn.net/?f=kt%3D%5Cfrac%7B1%7D%7B%5BA_t%5D%7D-%5Cfrac%7B1%7D%7B%5BA_o%5D%7D)
where,
k = rate constant = 
t = time = ?
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
= final concentration = 0.40 M
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial concentration = 2.16 M
Now put all the given values in the above expression, we get:
Therefore, the time taken by the reaction is
