The best answer is letter A.
The main factors that change the speed of enzymatic reactions are temperature, pH and substrate concentration (quantity). <span>There are enzymes that need other associated molecules to work. These molecules are called enzyme co-factors. They can be organic ions like mineral salts.</span>
Answer:
The correct answer is option a.
Explanation:

Equilibrium concentration cadmium ions = ![[Cd^{2+}]=0.0585 M](https://tex.z-dn.net/?f=%5BCd%5E%7B2%2B%7D%5D%3D0.0585%20M)
Equilibrium concentration fluoride ions = ![[F^{-}]=0.117 M](https://tex.z-dn.net/?f=%5BF%5E%7B-%7D%5D%3D0.117%20M)
Molar solubility is the maximum concentration of salt present in water in ionic form beyond that no more salt will exist in its ionic form and will settle down in bottom of the solution.
The molar solubility of the solid cadmium fluoride = 0.0585 M
..[1]

Due to addition of sodium fluoride will increase concentration of fluoride in the solution.And due to common ion effect the equilibrium will shift in backward direction in [1], that is precipitation of more cadmium fluoride.
Hence, decrease in solubility will be observed.
Answer:
67.6 years is the time the isotope take to decay from 0.900g to 0.170g
Explanation:
The radioactive decay follows first order law:
Ln [A] = -kt + ln[A]₀
<em>Where [A] is concentration after time t,</em>
<em>k is decay constant:</em>
<em>k = ln 2 / t(1/2)</em>
<em>k = ln2 / 28.1 years</em>
<em>k = 0.02467 years⁻¹</em>
<em>[A]₀ = Initial concentration.</em>
<em />
We can replace concentration and use the mass of the isotope:
Ln [A] = -kt + ln[A]₀
Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]
-1.667 = -0.02467 years⁻¹t
t =
<h3>67.6 years is the time the isotope take to decay from 0.900g to 0.170g</h3>