If I understand this right, the two elements are Nickel and Copper, elements 28 and 28, respectively. A nickel is worth 5 cents, and a penny, originally comprised of copper, is worth one - the total being six cents.
They both have 1 electron in their valence shell.....
Tops stops spinning because it doesn't have energy or ran out of force for example when you spin a top you give force to it then after 30 sec it going to stop going slower and slower that Is losing energy that's how tops stops spinning
Answer:
hope the inserted image will help :)
Explanation:
Answer: a) 
b) 
Explanation:
The reaction is :
Rate = Rate of disappearance of 
= Rate of appearance of 
Rate = ![-\frac{d[N_2O_5]}{2dt}](https://tex.z-dn.net/?f=-%5Cfrac%7Bd%5BN_2O_5%5D%7D%7B2dt%7D)
= ![\frac{d[NO_2]}{4dt}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%5BNO_2%5D%7D%7B4dt%7D)
Rate of disappearance of = 
= 
a) Rate of disappearance of =
Rate of appearance of =
b) Rate of appearance of = ![\frac{d[NO_2]}{dt}=2\times 1.7\times 10^{-4}}=3.4\times 10^{-4}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%5BNO_2%5D%7D%7Bdt%7D%3D2%5Ctimes%201.7%5Ctimes%2010%5E%7B-4%7D%7D%3D3.4%5Ctimes%2010%5E%7B-4%7D)
