Explanation:
The given data is:
The half-life of gentamicin is 1.5 hrs.
The reaction follows first-order kinetics.
The initial concentration of the reactants is 8.4 x 10-5 M.
The concentration of reactant after 8 hrs can be calculated as shown below:
The formula of the half-life of the first-order reaction is:

Where k = rate constant
t1/2=half-life
So, the rate constant k value is:

The expression for the rate constant is :

Substitute the given values and the k value in this formula to get the concentration of the reactant after time 8 hrs is shown below:

Answer: The concentration of reactant remains after 8 hours is 2.09x10^-6M.
Answer:
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. ... Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field.
Explanation:
The process through which Polonium is most likely to become stable is: B. alpha decay.
An unstable element refers to a chemical element that lose particles because its nucleus contain an excess of internal energy (neutron or proton).
This ultimately implies that, an unstable element is radioactive in nature.
In Science, some examples of an unstable element are:
Polonium is a chemical element with a large, unstable nucleus.
Basically, the most stable isotope of Polonium is Polonium-209, which typically undergoes an alpha decay to form lead-205 and the emission of an alpha particle.
⇒
----> 
In conclusion, we can deduce from the above chemical equation that Polonium is most likely to become stable through an alpha decay.
Read more: brainly.com/question/18214726
Actually, the ionic equation for this is a reversible
equation since codeine is a weak base. Any weak base or weak acids do not
completely dissociate which makes them a reversible process. The ionic equation
for this case is:
<span>C18H21O3N + H3O+ </span><=>
C18H21O3NH+ + H2O
Depends on the element it can by up to 3, 8, or maybe 16.