Chlorine is the correct answer so A
Answer:
A) The number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The options attached to the question are missing, but out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸.
B) The mass of a grain of iron is approximately (9 × 10⁻⁵) g
Explanation:
The options attached to the question are missing, after searching online, the image of the question was obtained, but it won't be attached to this solution in order not to violate the community guidelines and lead to deletion of answer.
But, out of the numbers presented in the options, 10¹⁷ is closest to 10¹⁸, hence, the number of atoms in a grain of iron is most similar to the number of meters between Earth and Vega.
The second part of the question asks for the approximate mass of a grain of iron.
1 atom of iron has a mass of (9 × 10⁻²³) g
1 grain of iron has about (1 × 10¹⁸) atoms of iron.
So, the mass of a grain of iron = (9 × 10⁻²³) × (1 × 10¹⁸) = (9 × 10⁻⁵) g
Hope this Helps!!!
The SI unit for mass is Kilogram (kg).
Answer:
pH = 13.1
Explanation:
Hello there!
In this case, according to the given information, we can set up the following equation:

Thus, since there is 1:1 mole ratio of HCl to KOH, we can find the reacting moles as follows:

Thus, since there are less moles of HCl, we calculate the remaining moles of KOH as follows:

And the resulting concentration of KOH and OH ions as this is a strong base:
![[KOH]=[OH^-]=\frac{0.00576mol}{0.012L+0.032L}=0.131M](https://tex.z-dn.net/?f=%5BKOH%5D%3D%5BOH%5E-%5D%3D%5Cfrac%7B0.00576mol%7D%7B0.012L%2B0.032L%7D%3D0.131M)
And the resulting pH is:

Regards!
It is
<span>b. strong acid vs. weak base.</span>