According to the statement there is a force of repulsion between the two objects. Remember that two objects must have the same charge so that they repel each other. In this way if the tape is repelled by a plastic pen that is negatively charged, this allows us to appreciate that the tape is also negatively charged. Now if the tape repels the sphere, therefore the sphere is also negatively charged.
Under these considerations the correct answers would be
2. Sodium ions from the salt water on your hand moved onto the sphere
4. The excess negative charge from the sphere spread out all over your body
6. Electrons from the sphere moved into the salt water on your skin, where they reacted with sodium ions
7. After you touched it, the metal sphere was very nearly neutral.
Answer:Expression given below
Explanation:
Given mass of spring
Compression in the spring
Let the spring constant be K
Using Energy conservation
potential energy stored in spring =Kinetic energy of Block
now conserving momentum
where 
is the final velocity
These are the characterstics of metal.
hope it helps u........
