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:
6
Explanation:
This atom is sulfur (if the electrons are equal to the protons/not an ion). You can tell the number of valence electrons by looking at the individual shell. The first shell (1s) can only hold 2 electrons. The second shell (2s and 2p) can hold 8 electrons. The third shell (3s and 3p), which is the valence shell, only has 6 out of its possible 8 electrons, so this atom has 6 valence electrons.
Answer:
6) solid- dots close together
liquid- a little bit farther apart than solid
gas- far apart
7) the movement of anything from a higher area of concentration to an area of lower concentration.
8) B. evaporation
9) The solute is the thing being dissolved, the solvent is the thing dissolving it, and the solution is the product of the solute and solvent.
10) D. regular brewed coffee
*I'm not exactly sure on #10 but I hope I could've helped a little at least
Answer:
Number of neutrons is equal to 148.