The core has positive charge<span>, the electrons have negative </span>charge. When you are rubbing<span> the </span>glass rod<span> with the </span>silk cloth<span>, electrons are stripped away from the atoms in the </span>glass<span> and transferred to the </span>silk cloth<span>. This leaves the </span>glass rod<span> with more </span>positive<span> than negative </span>charge<span>, so you get a net </span>positive charge<span>.</span>