The atomic number for iodine (I) = 53
The electron for I is:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵
Now, among the noble gases, Krypton (Kr) has an atomic number 36. Thus we can write:
I = [1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ ] 5s² 4d¹⁰ 5p⁵
I = [Kr] 5s² 4d¹⁰ 5p⁵
(or)
I = [Kr] 4d¹⁰ 5s² 5p⁵
It's already balanced since there is an equal number of elements on each side!
I hope this helps!
Answer:
Option B.
Explanation:
As any reaction of combustion, the O₂ is a reactant and the products are CO₂ and H₂O. Combustion reaction for ethane is:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
So 2 moles of ethane react with 7 moles of oxygen to make 4 moles of dioxide and 6 moles of water.
Then 2 moles of ethane will produce 4 moles of CO₂
Okay so molar mass is given, no. of moles is given and we have to calculate the weight or mass of the compound in gram.
the formula we will use here is= n=W/M
where n is no. of moles ,w is weight in gram which we have to find and M is molar mass or formula weight which is given.
so W=n x M
use this formula you'll get the answer
Question 1
The topmost layer of the rock would be layer B I think because its the most recent layer
Question 2
The answer should be "Organism X existed for a short period of time" because the other ones dont make sense and maybe if it existed for a short period of time there would be less fossils of it in the rock.
Question 3
The answer should be C because if it is next to the fossil that would mean it existed when the fossil did.
Question 4
I think the answer is radioactive dating because radioactive dating is a technique used to date materials such as rocks or carbon.