How Do Objects Become Electrically Charged

We will explore how electrical charge is created, how electrons are transferred, what makes objects become electrically charged, which type of objects can become electrically charged more easily than others, how an electric charge can be stored, and some properties of flowing electric charge below.

In general, an object becomes electrically charged through electron transfer when either an excess or deficiency of electrons is present around its atoms. If there are more electrons than normal, the object becomes negatively charged because electrons themselves have a negative charge. Conversely, the object becomes positively charged when there are fewer electrons than normal.

How Electrical Charge is Created

An electrical charge is created when materials come into contact with one another. Whilst in contact, electrons transfer from one to the other. Whether this electron transfer happens or not, how much it happens, how quickly, and in which direction depends on the atoms of the materials. Some are more or less willing to give or accept electrons than others.

If the electrons transfer from one object to another, then one object will have more than its normal amount of electrons, and the other will have less. The object with excess electrons becomes negatively charged, while the other with a deficiency of electrons will become positively charged.

Normally, an object is balanced or electrically neutral if it neither has an excess of electrons nor a deficiency of electrons. In this case, the number of electrons equals the number of protons in the nuclei of atoms. Objects in this condition are neither negatively nor positively charged. Note that it is the number of electrons in relation to the number of protons that determines whether there are more or fewer electrons than normal.

We have described three conditions concerning electrical charge:

• Electrically neutral object – Neither excess nor deficiency of electrons because the number of electrons equals the number of protons.
• Negatively charged object – An excess of electrons because there are more electrons than protons.
• Positively charged object – A deficiency of electrons because there are fewer electrons than protons.

What Happens to Electrically Charged Objects?

A common example to easily demonstrate this is rubbing your hair with a balloon made of insulating material. Electrons move from the hair to the balloon’s surface, making the balloon negatively charged and the person positively charged.

If you make another balloon negatively charged by doing the same and bring the two balloons to close, you will notice that they will repel each other. This happens because they both carry the same type of charge.

The law is that two objects with the same charge will repel one another, and two oppositely charged objects will attract each other.

Types of Objects That Charge Easily

To know what types of objects charge easily if you bring the charged balloon near one end of an aluminum can (without direct contact), the can will act as a neutral conductor. Electrons will transfer and accumulate on the opposite end of the can due to the above law.

Consequently, you might see the can tilt or roll to take this position. If you bring the two objects into direct contact, the electron flow will cause both to be negatively charged, and they will soon repel one another. The opposite effect, called induction, can be demonstrated if we touch the can’s negative end to leave the can positively charge instead.

They can behave in this way because, as a metal, it is a good conductor of electricity. It has free electrons that can move about and between objects in contact. This is different from insulators, which do not have free electrons and do not conduct electricity.

Furthermore, the above demonstration shows that objects become electrically charged in two ways: either by contact or by induction.

Storing and Moving Electrical Charges

Electrical charges carry the EM (electromagnetic) field. Specifically, when objects carry a non-moving electrical charge, electrostatic forces are involved, and electric and magnetic forces are involved when the charges are moving. The electric field surrounding an electrically charged object is equal to the force experienced by a positive unit charge. [1, 2]

Storing Electrical Charge

A capacitor is an electronic component that can store electrical charge and energy for a period. The amount of charge it can store is called capacitance, measured in farads. It has a restoring force proportional to the amount of charge stored. Batteries are also specially designed for this purpose.

Flowing Electrical Charge

The quantity of electrical charge that flows through an object is called current, which is measured in amperes. This is the opposite of static electricity, where no current is produced. When an electrical charge accelerates, it produces EM radiation.

FAQs

Here are direct answers to each of the questions presented in the introduction based on the related content covered in this article:

Take a look at some of our related articles below.

• How to remove static electricity from machinery
• How many amps are needed to charge an electric car
• Is red wire positive or negative

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References

[1] FHSST. The free high school science texts: A textbook for high school students studying physics. Retrieved from http://savannah.nongnu.org/projects/fhsst. 2003.

[2] Larry Kirkpatrick & Gregory E. Francis. Physics: A conceptual world view. Cengage Learning. 2009.