Question

A plastic rod that has been charged negatively touches a neutral metal sphere. What kind of charged particle was transferred between the rod

Answer 1

Negative particles will be transferred to the sphere,

Assuming the sphere is not grounded the sphere will be negatively charged when the plastic rod is withdrawn,

(The sphere can be positively charged by grounding the sphere and bringing the rod close to the sphere and then remove the grounding to the sphere)

Care must be taken in noting if and when the sphere is grounded.