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.
<h2>Answer:</h2>
A) 3 atoms - 1 atom of Carbon and 2 atoms of oxygen.
B) 2 atoms of Nitrogen.
C) 6 atoms - 2 Carbon atoms, 2 Hydrogen atoms, and 2 Oxygen atoms.
<h2>Explanations:</h2>
A molecule is a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound. Molecules are made up of atoms.
According to the following information, we are to find the number of atoms in the given molecules.
A) For carbon dioxide CO₂, this molecule is made of 3 atoms - 1 atom of Carbon and 2 atoms of oxygen.
B) For the compound N₂, this molecule is made up of 2 atoms of Nitrogen.
C) For the compound CHCOOH, this molecule consists of 6 atoms - 2 Carbon atoms, 2 Hydrogen atoms, and 2 Oxygen atoms.
Answer:
1.64x10⁻¹⁸ J
Explanation:
By the Bohr model, the electrons surround the nucleus of the atom in shells or levels of energy. Each one has it's energy, and the electron doesn't fall to the nucleus because it can reach another level of energy, and then return to its level.
When the electrons go to another level, it absorbs energy, and then, when return, this energy is released, as a photon (generally as luminous energy). The value of the energy can be calculated by:
E = hc/λ
Where h is the Planck constant (6.626x10⁻³⁴ J.s), c is the light speed (3.00x10⁸ m/s), and λ is the wavelength of the photon.
The wavelength can be calculated by:
1/λ = R*(1/nf² - 1/ni²)
Where R is the Rydberg constant (1.097x10⁷ m⁻¹), nf is the final orbit, and ni the initial orbit. So:
1/λ = 1.097x10⁷ *(1/1² - 1/2²)
1/λ = 8.227x10⁶
λ = 1.215x10⁻⁷ m
So, the energy is:
E = (6.626x10⁻³⁴ * 3.00x10⁸)/(1.215x10⁻⁷)
E = 1.64x10⁻¹⁸ J
Larges of flowing ice called glaciers are typically found near Earth's poles and other cold regions.