Question

a glass marble is rubbed against a piece of silk. as a result the piece of fabric acquires extra electrons. what happens to the glass marble? check all that apply. view available hint(s) the marble has lost the same number of electrons acquired by the piece of silk. the marble has acquired the same number of electrons acquired by the piece of silk. the marble acquires a positive charge and repels the piece of silk. the marble acquires a positive charge and attracts the piece of silk. the marble acquires a negative charge and attracts the piece of silk. the marble acquires a negative charge and repels the piece of silk.

Explanation:

1. When the silk acquires extra electrons (gains electrons), the glass marble must lose electrons (since charge is conserved in the rubbing process). So the number of electrons the marble loses is equal to the number the silk gains. Thus, "The marble has lost the same number of electrons acquired by the piece of silk" is correct.
2. Since the marble loses electrons, it has more protons than electrons, so it acquires a positive charge. Opposite charges attract, so a positively charged marble will attract the negatively charged silk (because silk gained electrons, so it's negative). So "The marble acquires a positive charge and attracts the piece of silk" is correct. The option saying it repels is wrong (like charges repel, opposite attract). The options about the marble acquiring negative charge are wrong because it lost electrons. The option about acquiring same number of electrons as silk is wrong (silk gained, marble lost).

Answer:

• The marble has lost the same number of electrons acquired by the piece of silk.
• The marble acquires a positive charge and attracts the piece of silk.