Final answer:
Two metal spheres attracting each other implies they carry opposite charges. Upon contact, charges redistribute across metal spheres until an equilibrium is reached, typically leading to either both spheres having no net charge or having the same charge if they were initially charged alike. A negatively charged rod brought close to two spheres that are in contact will induce a negative charge on both spheres.
Step-by-step explanation:
When two metal spheres attract each other, we can infer that they carry opposite charges, as like charges repel and unlike charges attract. If the right-hand sphere is positively charged and the left-hand sphere is unknown, it must have a negative charge for them to attract each other.
Sharing of Charges
When the spheres are brought into contact, the electrons will redistribute until both spheres have the same charge. The outcome will depend on the initial charges of both spheres. If they both have the same type of charge (both positive or both negative), they will repel each other after contact because the charge will equally distribute between them. If they have opposite charges, they will attract each other until they touch and share the charge, and then they may repel each other if the shared charge is like.If a negatively charged rod is brought close to two metal balls in contact, the balls will both end up negatively charged after being separated, leading them to repel each other. If the second ball is momentarily grounded while near the rod, it will lose its excess negative charge, resulting in the ball having a neutral charge while the rod is still present.
Charge Equilibrium
In the case of two charged metal spheres, Sphere A with −5 nC and Sphere B with −3 nC, brought into contact and then separated, the charges will redistribute and each sphere will end up with the average of the initial charges, which is −4 nC each. This is a consequence of charge conservation and the nature of conductors to distribute charge evenly.