Given :
The distance between a point charge and a neutral atom and is multiplied by a factor of 5.
To Find :
By what factor does the force on the neutral atom by the point charge change.
Solution :
We know, electrostatic force between two object is directly proportional to product of charge and inversely proportional to distance between them.
Now, charge in neutral atom is 0 C.
So, the electrostatic force between two of them is also 0 N.
Therefore, by changing distance between the charge the forces did no change ( it remains zero).
A physical change is a change to a sample of matter in which some properties of the material change, but the identity of the matter does not. Physical changes can further be classified as reversible or irreversible. The melted ice cube may be refrozen, so melting is a reversible physical change.
Answer : The mass percentage of isopropyl alcohol in the solution is, 59.4 %
Explanation :
To calculate the mass percentage of isopropyl alcohol in the solution, we use the equation:

Mass of isopropyl alcohol = 6.68 g
Mass of isopropyl alcohol solution = 3.97 g
Putting values in above equation, we get:

Thus, the mass percentage of isopropyl alcohol in the solution is, 59.4 %