The word atom comes from the Greek atomos which means indivisible, indivisible (excepted in the nuclear reactions). It was therefore perfectly suited to the concept of atom when it was developed by chemists in the early nineteenth century, ie as the smallest part of a pure body.
So the atom of aluminum will remain unchanged, whatever the reaction it will undergo, it is only its molecular form that will change.
Answer:
0.00915 M of 
remain after 5.16 seconds.
Explanation:
Using integrated rate law for first order kinetics as:
![[A_t]=[A_0]e^{-kt}](https://tex.z-dn.net/?f=%5BA_t%5D%3D%5BA_0%5De%5E%7B-kt%7D)
Where,
![[A_t]](https://tex.z-dn.net/?f=%5BA_t%5D)
is the concentration at time t
![[A_0]](https://tex.z-dn.net/?f=%5BA_0%5D)
is the initial concentration
Given that:
The rate constant, k = 
s⁻¹
Initial concentration = 0.054 M
Final concentration = ? M
Time = 5.16 s
Applying in the above equation, we get that:-
![[A_t]=0.054e^{-0.344\times 5.16}\ M=\frac{1\times \:0.054}{e^{1.77504}}\ M=0.00915\ M](https://tex.z-dn.net/?f=%5BA_t%5D%3D0.054e%5E%7B-0.344%5Ctimes%205.16%7D%5C%20M%3D%5Cfrac%7B1%5Ctimes%20%5C%3A0.054%7D%7Be%5E%7B1.77504%7D%7D%5C%20M%3D0.00915%5C%20M)
<u>0.00915 M of remain after 5.16 seconds.</u>
We need a image to answer this sorry
Yes. Percent yield shows how efficient one's method is. If his isolated caffeine proved to be at only 1.5%, compared to least 50% as in many of the previous experiments, the student should be very concerned as it shows that something caused the yield to sharply drop.
