That John Dalton was an English chemist that was most famous for proposing atomic chemistry.He proposed atomic theory in 1803,which states that all matter is composed of small indivisible particles called atoms.
Answer:

Explanation:
First write all numerators above the common denominator
4/5 - 1/2 - 1/2=
- 1/2
Subtract the numbers
- 1/2 =
-
Write all numerators above the least common denominator 10
-
=

Subtract the numbers and you got your answer :)
Answer:
Biggest Radii V²⁺ > V³⁺ > V⁴⁺ > V⁵⁺ Smallest Radii
General Formulas and Concepts:
- Periodic Trends: Atomic/Ionic Radii
- Coulomb's Law
Explanation:
The Periodic Trend for Atomic Radii is down and to the left. Therefore, the element with the largest radius would be in the bottom left corner of the Periodic Table.
Anions will always have a bigger radii than the parent radii. When we add e⁻ to the element, we are increasing the e⁻/e⁻ repulsions. This will cause e⁻ to repel themselves more and thus create more space, increasing the radii size.
Cations will always have smaller radii than the parent radii. When we remove e⁻ from the element, we are decreasing e⁻/e⁻ repulsions. Since there are less e⁻, there is no need for more space and thus decreases the radii size.
Since Cations are smaller than the parent radii, the more e⁻ we remove, the smaller it will become.
Therefore, the least removed e⁻ Vanadium would be the largest and the most removed e⁻ Vanadium would be the smallest.
0.428571429 moles is your exact answer. Hope this helps!!! (: