Answer:
B) A series of chemical reactions where enzymes work one at a time to convert a reactant into intermediates and the intermediates into a final product.
Explanation:
In our cells there are multiple chemical reactions happening all the time to convert the elements we ingest (food, water, air) into the products the organism needs.
This processes can be very complex and offen involves various reactions (steps). Also, many of this reactions need to by catalized by enzymes in order to happen.
Crust, Mantle, Outer core, Inner Core
Combustion is not a physical change instead it's a chemical change because when we burn things we cannot regain it's original form.
Answer:
Degree of ionization = 0.0377
pH of the solution = 1.769
Explanation:
Initial concentration of HF = 0.45 M
Initial 0.45 0 0
At equi 0.45 - x x x
Equilibrium constant = ![\frac{[H^+][F^-]}{HF}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BH%5E%2B%5D%5BF%5E-%5D%7D%7BHF%7D)
![6.8 \times 10^{-4}= \frac{[x][x]}{0.45 - x}](https://tex.z-dn.net/?f=6.8%20%5Ctimes%2010%5E%7B-4%7D%3D%20%5Cfrac%7B%5Bx%5D%5Bx%5D%7D%7B0.45%20-%20x%7D)
x = 0.017 M
x = Cα
α = Degree of ionization
C = Concentration
Degree of ionization = 
![pH = -log[H^+]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH%5E%2B%5D)
[H^+]=0.017 M
![pH = -log[0.017]](https://tex.z-dn.net/?f=pH%20%3D%20-log%5B0.017%5D)
= 1.769
