Final answer:
Electrically neutral objects can become charged through the transfer of electrons, following the conservation of charge. Charging can happen via contact, conduction, or induction, resulting in either a negative or positive charge due to the loss or gain of electrons.
Step-by-step explanation:
Electrically neutral objects can become electrically charged through the process of transferring charge. This can occur even though charge itself cannot be created or destroyed, due to the law of conservation of charge. Neutral objects contain both positive charge and negative charge, but in equal amounts, making them appear neutral.
Objects may become charged by contact, conduction, or induction. When charging by contact or by being rubbed against another material, electrons can be transferred, leaving one object with an excess of electrons, becoming negatively charged, and the other with a deficit, becoming positively charged. This process is known as the transfer and separation of charge. Conductors allow for the easy movement of charge, whereas insulators do not.
The negative charge is generally the charge that moves as it is carried by electrons, which are much more mobile than protons. Protons are bound within the nucleus of atoms and hence do not move freely in solid materials. When a previously neutral object loses electrons, it becomes positively charged, and when it gains electrons, it becomes negatively charged. The overall number of charges in the universe remains constant, thus adhering to the conservation of charge.