Answer:
C. effusion because there is a movement of a gas through a small opening into a larger volume
Explanation:
Effusion makes fluid/gas molecules move to the container with less pressure or larger volume. In diffusion, the movement should work two ways even though one side might receive more. But in effusion, the movement is rather one way.
This case shows how effusion work because its not the concentration that makes the balls moving to the bottom part of the container. No ball moving from bottom container to top either.
Answer:
- 0.0249% Sb/cm

Explanation:
Given that:
One surface contains 1 Sb atom per 10⁸ Si atoms and the other surface contains 500 Sb atoms per 10⁸ Si atoms.
The concentration gradient in atomic percent (%) Sb per cm can be calculated as follows:
The difference in concentration = 
The distance
= 0.2-mm = 0.02 cm
Now, the concentration of silicon at one surface containing 1 Sb atom per 10⁸ silicon atoms and at the outer surface that has 500 Sb atom per 10⁸ silicon atoms can be calculated as follows:

= - 0.0249% Sb/cm
b) The concentration
of Sb in atom/cm³ for the surface of 1 Sb atoms can be calculated by using the formula:

Lattice parameter = 5.4307 Å; To cm ; we have
= 

= 
The concentration
of Sb in atom/cm³ for the surface of 500 Sb can be calculated as follows:

= 
= 
Finally, to calculate the concentration gradient



About 2,500 grams Ans balkfdoaks;
I’m pretty sure it is A at least that’s what we did at our school to test this
Answer:
a. the solution will be weakly basic.
b. Greater than 7 because CN⁻ is a stronger base than NH₄⁺ is an acid.
Explanation:
a. The fluoride ion (F⁻) reacts with water thus:
F⁻ + H₂O → HF + OH⁻
That means that fluoride ions produce OH⁻ ions in solution doing <em>the solution will be weakly basic.</em>
b. The acidic equilibrium of NH₄⁺ is:
NH₄⁺ ⇄ NH₃ + H⁺ with a ka of 5,6x10⁻¹⁰.
The basic equilibrium of CN⁻ is:
CN⁻ + H₂O → HCN + OH⁻ with a kb of 2x10⁻⁵
That means that the production of OH⁻ from CN⁻ is higher than production of H⁺ from NH₄⁺. The CN⁻ is a stronger base than NH₄⁺ is an acid.
Thus, the pH of a salt solution of NH₄CN would be <em>Greater than 7 because CN⁻ is a stronger base than NH₄⁺ is an acid.</em>
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I hope ot helps!