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Charge and Charging - help14

When it comes to static electricity, objects and their behavior can be understood in terms of two simple particles - protons and electrons. Protons are the tightly-bound, positively-charged particles that are in the nucleus of atoms and electrons are the loosely-bound, negatively-charged particles located ouside the nucleus of atoms. The charge that an object possesses depends on the relative number of these particles. The charge that an object becomes can be explained in terms of the movement of electrons.

There are two similar versions of this question. Here is one of the versions:

Version 1:
Two students are experimenting with two neutral objects – a rubber balloon and a sample of animal fur. They rub the two together and the balloon becomes charged negatively and the fur becomes charged positively. Complete the analysis of this situation.

How did the balloon become charged?
Electrons were added to the balloon.
Protons were added to the balloon.
Electrons were removed from the balloon.
Protons were removed from the balloon.

Like all questions in Activity 3: Analyze This!, you have to do two basic things: (1) compare the numbers of protons and electrons for the two objects in the Before and the After state, and (2) indicate how the neutral object acquired its charge during the charging process.

Comparing the #Protons and #Electrons
To compare the # of protons to the # of electrons, you will need to know ...

Electrons are negatively charged.
Protons are positively charged.
The amount of charge on one electron is equal to the amount of charge on one proton.

And so, neutral objects have equal numbers of these particles such that there is no overall charge (i.e., neutral). Positively-charged objects have more of the positive protons than the negative electrons leaving them with an overall positive charge. And negatively-charged objects have more of the negative electrons than the positive protons leaving them with an overall negative charge.

How do Neutral Objects Become Charged?
Neutral objects have a balance of the two types of charge; they have equal numbers of the positive protons and negative electrons. When a neutral object becomes charged, this balance is disrupted by the movement of electrons. Protons are tightly-bound within the nucleus of the atom; so object charging never occurs by means of proton movement. This allows you to rule out two of the four answer options.

Neutral objects become negatively-charged when they acquire more electrons than protons. This occurs when electrons are added to the object's atoms. On the other hand, neutral objects become positively-charged when they acquire more protons than electrons. Since protons can never move, a positive-charging process involves the loss of electrons from a neutral object. Having lost electrons, the protons will then out-number the electrons.

Try this link to The Physics Classroom Tutorial for more help with understanding what must happen for neutral objects to become charged (or vice versa):

Neutral vs. Charged Objects