Answer:
Explanation:
1 mole of iron is 56 grams (rounded)
x mole of iron is 38 grams (given
1/x = 56/38 Cross multiply
56x = 38*1 Divide by 56
x = 38/56
x = 0.679 mols of iron
1 mol of anything = 6.02 * 10^23
0.678 mols of iron = x
1/0.679 = 6.02 *10^23 /x
x = 0.679 * 6.02*10^23
x = 4.09 * 10 ^23
So there are 4.09 * 10^23 atoms of Fe in 38 grams of iron
It’s aluminum because electrons and protons are basically the same thing just in different places on a electron cloud and the atomic number is 13 so I think it’s aluminum.
The correct answer is option E.
Explanation:
The pH of the solution is defined as negative logarithm of hydrogen ions concentration in a solution. Mathematically written as:
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
The pOH of the solution is defined as negative logarithm of hydroxide ions concentration in a solution. Mathematically written as:
![pOH=-\log[OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%5BOH%5E-%5D)
The sum of ph and pOH is equal to 14.
pH + pOH = 14
A solution has a pH of 4.20.
![pOH=9.8=-\log[OH^-]](https://tex.z-dn.net/?f=pOH%3D9.8%3D-%5Clog%5BOH%5E-%5D)
![[OH^-]=1.58\times 10^{-10} M\approx 6.0\times 10^{-10} M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.58%5Ctimes%2010%5E%7B-10%7D%20M%5Capprox%206.0%5Ctimes%2010%5E%7B-10%7D%20M)
Hence, the correct answer is option E.
The correct answer for this question is letter C. Newland's Law of Octaves was rejected mainly because it could not hold good for elements heavier than calcium. The relationship between the octaves started to break down since it was unable to accommodate newly discovered elements.
