The electron configuration for a neutral atom of oxygen would be the final option:
O : 1s^2 2s^2 2p^4.
Knowing that this is a neutral atom of oxygen, and that it posses the same number of electrons and protons, the total number of electrons would be 8. Which can be found out by adding the exponents for each subshell.
Answer:
A
Explanation:
all the other answers are wrong or not applicable. hope this helps :)
Answer:
7.14%
Explanation:
From the question,
percentage by mass hydrogen in C₄H₈O₃ (h) = mass of hydrogen present in C₄H₈O₃(m)/molar mass of C₄H₈O₃ (m')
h = (m'/m)×100..................... Equation 1
Given: m' = (14×4)+(1×8)+(16×3) = 56+8+48 = 112 g, m = (1×8) = 8 g
Substitute these values into equation 1
h = (8/112)×100
h = 7.14%.
Hence the percentage of hydrogen in 70 g of C₄H₈O₃ is 7.14%
Answer:
When this equation is solved, the two values of the unknown are 0.0643 and -0.082
Explanation:
Given
--- the actual equation
Required
The values of x
We have:
![1.77 * 10^{-2} = \frac{x^2}{0.298 - x}](https://tex.z-dn.net/?f=1.77%20%2A%2010%5E%7B-2%7D%20%3D%20%5Cfrac%7Bx%5E2%7D%7B0.298%20-%20x%7D)
Cross Multiply
![1.77 * 10^{-2} * (0.298 - x)= x^2](https://tex.z-dn.net/?f=1.77%20%2A%2010%5E%7B-2%7D%20%2A%20%280.298%20-%20x%29%3D%20x%5E2)
Multiply both sides by 100
![1.77 * (0.298 - x)= 100x^2](https://tex.z-dn.net/?f=1.77%20%20%2A%20%280.298%20-%20x%29%3D%20100x%5E2)
Open bracket
![0.52746 - 1.77x= 100x^2](https://tex.z-dn.net/?f=0.52746%20-%201.77x%3D%20100x%5E2)
Rewrite as:
![100x^2 + 1.77x - 0.52746 =0](https://tex.z-dn.net/?f=100x%5E2%20%2B%201.77x%20-%200.52746%20%3D0)
Using quadratic formula:
![x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-b%20%5C%C2%B1%20%5Csqrt%7Bb%5E2%20-%204ac%7D%7D%7B2a%7D)
Where:
![a = 100; b = 1.77; c = -0.52746](https://tex.z-dn.net/?f=a%20%3D%20100%3B%20b%20%3D%201.77%3B%20c%20%3D%20-0.52746)
So, we have:
![x = \frac{-1.77 \± \sqrt{1.77^2 - 4*100*- 0.52746 }}{2*100}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-1.77%20%5C%C2%B1%20%5Csqrt%7B1.77%5E2%20-%204%2A100%2A-%200.52746%20%7D%7D%7B2%2A100%7D)
![x = \frac{-1.77 \± \sqrt{214.1169}}{2*100}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-1.77%20%5C%C2%B1%20%5Csqrt%7B214.1169%7D%7D%7B2%2A100%7D)
![x = \frac{-1.77 \± 14.63}{200}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-1.77%20%5C%C2%B1%2014.63%7D%7B200%7D)
Split
![x = \frac{-1.77 + 14.63}{200}\ or\ x = \frac{-1.77 - 14.63}{200}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B-1.77%20%2B%2014.63%7D%7B200%7D%5C%20or%5C%20x%20%3D%20%5Cfrac%7B-1.77%20-%2014.63%7D%7B200%7D)
![x = \frac{12.86}{200}\ or\ x = \frac{-16.40}{200}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B12.86%7D%7B200%7D%5C%20or%5C%20x%20%3D%20%5Cfrac%7B-16.40%7D%7B200%7D)
![x = 0.0643\ or\ x = -0.082](https://tex.z-dn.net/?f=x%20%3D%200.0643%5C%20or%5C%20x%20%3D%20-0.082)
A. Atoms. Because I learned this in 6th grade.