curie, <span>one basic unit are used for measuring radiation. One is the </span>curie,<span> named after Marie and Pierre Curie. </span>
Answer : The original concentration of copper (II) sulfate in the sample is, 
Explanation :
Molar mass of Cu = 63.5 g/mol
First we have to calculate the number of moles of Cu.
Number of moles of Cu = 
Now we have to calculate the number of moles of 
Number of moles of Cu = Number of moles of 
Number of moles of
= 
Now we have to calculate the molarity of 

Now put all the given values in this formula, we get:

To change mol/L into g/L, we need to multiply it with molar mass of 
Molar mass of
= 159.609 g/mL
Concentration in g/L = 
Thus, the original concentration of copper (II) sulfate in the sample is, 
Hydrogen peroxide is a powerful oxidizer. When exposed to sunlight it quickly decomposes to form water and oxygen as given by the following equation.
2H2O2(aq) → 2H2O(l) + O2(g)
Hydrogen peroxide is commercially available as a 30% w/w solution, which is the concentration that would facilitate the above reaction. This implies that the concentration would be 30 g of H2O2 in 100 g of the solution.
Lithium has the lowest. if fluorine is the highest then lithium is the lowest. i hope this helps you out!
Identical electron configurations : K⁺ and Cl⁻
<h3>Further explanation </h3>
In an atom, there are levels of energy in the shell and sub-shell
This energy level is expressed in the form of electron configurations.
Charging electrons in the sub-shell uses the following sequence:
<em>1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc. </em>
S²⁻ : [Ne] 3s²3p⁶
Cl : [Ne] 3s²3p⁵
K⁺ : 1s² 2s² 2p⁶ 3s² 3p⁶
Cl⁻ : 1s² 2s² 2p⁶ 3s²3p⁶
S :[Ne] 3s²3p⁴
Ar : [Ne] 3s²3p⁶
Cl⁻ : 1s² 2s² 2p⁶ 3s²3p⁶
K : 1s² 2s² 2p⁶ 3s² 3p⁶4s¹