Answer:
(a) 0.8 s
(b) t = 7.2 s
Explanation:
(a) Half life expression for second order kinetic is:
![t_{1/2}=\frac{1}{k[A_o]}](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D%5Cfrac%7B1%7D%7Bk%5BA_o%5D%7D)
Where,
is the initial concentration = 1.0 M
k is the rate constant = 1.25 M⁻¹s⁻¹
So,

Half life = 0.8 s
(b) Integrated rate law for second order kinetic is:
![\frac{1}{[A_t]} = \frac{1}{[A]_0}+kt](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5BA_t%5D%7D%20%3D%20%5Cfrac%7B1%7D%7B%5BA%5D_0%7D%2Bkt)
Where,
is the final initial concentration
For 90% completion, 10% is left. so,
![[A_t]=\frac {10}{100}\times 1.0=0.1\ M](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5Cfrac%20%7B10%7D%7B100%7D%5Ctimes%201.0%3D0.1%5C%20M)
So,

t = 7.2 s
Answer:
I don't understand what you are asking
The answer is: D.unstable nuclei emitting high-energy particles as they formed more stable compositions.
Those high-energy particles are alpha particles
, beta particles
, gamma radiation.
For example, the decay chain of ²³⁸U is called the uranium series.
Decay start with U-238 and ends with Pb-206. There are several alpha and beta minus decays.
Antoine Henri Becquerel (1852 – 1908) was a French physicist and the first person to discover evidence of radioactivity.
Becquerel wrapped fluorescing crystal (uranium salt potassium uranyl sulfate) in a cloth, along with the photographic plate and a copper Maltese cross.
Several days later, he discovered that a image of the cross appeared on the plate.
The uranium salt was emitting radiation.
Because of this discovery, Becquerel won a Nobel Prize for Physics in 1903, which he shared with Marie Curie and Pierre Curie.
Answer:
If More solute is added and it does not dissolve,then the original solution was saturated. if the added solute dissolves,then the original solution was unsaturated. A solution that has been allowed to reach equilibrium but which has extra undissolved solute at the bottom of the container must be saturated.