Ans 1. Both
Ans 2. Once inside plants, carbon moves through food chains, where organisms become nutrients including herbivores, carnivores and ultimately, decomposers. Once buried in the soil, carbon can be converted into fossil fuels over long periods of time and then also reenter the atmosphere by combustion. The Law of Conservation of Matter states that matter cannot be created or destroyed. The carbon cycle is an example of the Law
Ans 3. Most of the chemical energy needed for life is stored in organic compounds as bonds between carbon atoms and other atoms. The law of conservation of energy states that energy can not be created or destroyed. Thus, just like matter energy is also conserved in the process.
Hope it helps
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.
A Neutralisation reaction, the alkali is neutralizing the acid.
<u>Answer:</u> The time taken by the reaction is 84.5 seconds
<u>Explanation:</u>
The equation used to calculate half life for first order kinetics:
where,
= half-life of the reaction = 9.0 s
k = rate constant = ?
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
......(1)
where,
k = rate constant = 
t = time taken for decay process = 50.7 sec
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = ?
[A] = amount left after decay process = 0.0741 M
Putting values in equation 1, we get:
![0.077=\frac{2.303}{50.7}\log\frac{[A_o]}{0.0741}](https://tex.z-dn.net/?f=0.077%3D%5Cfrac%7B2.303%7D%7B50.7%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B0.0741%7D)
![[A_o]=3.67M](https://tex.z-dn.net/?f=%5BA_o%5D%3D3.67M)
Now, calculating the time taken by using equation 1:
![[A]=0.0055M](https://tex.z-dn.net/?f=%5BA%5D%3D0.0055M)
Putting values in equation 1, we get:
Hence, the time taken by the reaction is 84.5 seconds
