To illustrate the magnitude of 1 Coulomb, an object would need an excess of 6.25 x 10 18 electrons to have a total charge of -1 C. Because one Coulomb of charge is an abnormally large quantity of charge, the units of microCoulombs (♜) or nanoCoulombs (nC) are more commonly used as the unit of measurement of charge. Just as mass is measured in grams or kilograms, charge is measured in units of Coulombs (abbreviated C). The charge possessed by an object is often expressed using the scientific unit known as the Coulomb. Like mass, the charge of an object is a measurable quantity. When it comes to the drama of static electricity, electrons and protons become the main characters. Their role in the atom is merely to provide stability to the nucleus, a subject not discussed in The Physics Classroom. Their presence (or absence) will have no direct bearing upon whether an object is charged or uncharged. Neutrons, being electrically neutral play no role in this unit. In this discussion of electrically charged versus electrically neutral objects, the neutron has been neglected. Objects with more electrons than protons are charged negatively objects with fewer electrons than protons are charged positively. The principle stated earlier for atoms can be applied to objects. And neutral objects have a balance of charge - equal numbers of protons and electrons. Charged objects have an imbalance of charge - either more negative electrons than positive protons or vice versa. For now, it is sufficient to say that objects that are charged contain unequal numbers of protons and electrons.

The cause and mechanisms by which this movement of electrons occurs will be the subject of Lesson 2. In general, for electrons to make a move from the atoms of one material to the atoms of another material, there must be an energy source, a motive, and a low-resistance pathway. And as clothes tumble in the dryer, it is highly likely that electrons on one piece of clothing will move from the atoms of the clothing onto the atoms of another piece of clothing. If you were to walk across the carpeting towards the door of the room, electrons would likely be scuffed off the atoms of your shoes and moved onto the atoms of the carpet. Even as you read the words of this web page, some electrons are likely moving through the monitor and adhering to your clothing (assuming that you are using this resource online) (and wearing clothes). The process of an electron leaving one material object to reside (perhaps only temporarily) in another object is a common everyday occurrence. The electrons contained within the objects are prone to move or migrate to other objects. In short, electrons are migrants - constantly on the move and always ready to try out a new atomic environment.Īll objects are composed of these atoms. Similarly, electrons within atoms of other materials can be persuaded to leave their own electron shells and become members of the electrons shells of other atoms of different materials. While the electrons are attracted to the protons of the nucleus, the addition of energy to an atom can persuade the electrons to leave an atom. The protons are tightly bound within the nucleus and not removable by ordinary measures. In the previous section of Lesson 1, an atom was described as being a small and dense core of positively charged protons and neutral neutrons surrounded by shells of negatively charged electrons. Conversely, any particle that contains more electrons than protons is said to be negatively charged.Ĭharged Objects as an Imbalance of Protons and Electrons Any particle, whether an atom, molecule or ion, that contains less electrons than protons is said to be positively charged. On the other hand, if an atom has an unequal number of protons and electrons, then the atom is electrically charged (and in fact, is then referred to as an ion rather than an atom). Thus, if an atom contains equal numbers of protons and electrons, the atom is described as being electrically neutral. A proton and an electron have an equal amount but an opposite type of charge. The amount of charge on a single proton is equal to the amount of charge possessed by a single electron. The number of electrons that surround the nucleus will determine whether or not an atom is electrically charged or electrically neutral. And an atom containing 8 protons is an oxygen atom. An atom containing 6 protons is a carbon atom. An atom containing one proton is a hydrogen atom (H). Atoms of each element are distinguished from each other by the number of protons that are present in their nucleus. There are different types of atoms, known as elements.

As discussed in a previous section of Lesson 1, atoms are the building blocks of matter.

Proton charge quantity