Question

You observe that a negatively charged plastic pen repels a chargedpiece of magic tape. You then observe that the same piece of tapeis repelled when brought near a metal sphere. You are wearingrubber soled shoes, and you touch the metal sphere with your hand.After you touch the metal sphere, you observe that the tape isattracted to the metal sphere. Which of the following statementscould be true? Check all that apply.
1. Electronsfrom the sphere traveled through your body into theEarth

2. Sodiumions from the salt water on your hand moved onto thesphere

3. Chlorideions from the salt water on your hand moved onto thesphere

4. Theexcess negative charge from the sphere spread out all over yourbody

5. Electronsfrom your hand moved onto the sphere

6. Electronsfrom the sphere moved into the salt water on your skin, where theyreacted with sodium ions

7. Afteryou touched it, the metal sphere was very nearlyneutral.

Answer 1

According to the statement there is a force of repulsion between the two objects. Remember that two objects must have the same charge so that they repel each other. In this way if the tape is repelled by a plastic pen that is negatively charged, this allows us to appreciate that the tape is also negatively charged. Now if the tape repels the sphere, therefore the sphere is also negatively charged.

Under these considerations the correct answers would be

2. Sodium ions from the salt water on your hand moved onto the sphere

4. The excess negative charge from the sphere spread out all over your body

6. Electrons from the sphere moved into the salt water on your skin, where they reacted with sodium ions

7. After you touched it, the metal sphere was very nearly neutral.