Uploaded September 2020 | Updated September 2026, 1 hour ago
We rely heavily on electricity in our daily lives but rarely do we think about what it actually is. Today we will discuss the basics of electricity and hopefully gain an appreciation for this wonderful source of energy at our disposal.
To understand the basics of electricity, we must first understand the basics of the atom. Everything in the universe is made of atoms. They are microscopic particles that make up all matter and are considered to be the building blocks of the universe. An atom is made up of even smaller particles called protons, neutrons, and electrons. Protons and electrons both carry an electrical charge which is a force within the particles. Protons have a positive charge while electrons have a negative charge. The positive charge is usually represented by a plus sign and the negative charge is represented by a minus sign. Neutrons do not have any charge and are therefore considered neutral. Atoms have a center known as the nucleus, which is made up of protons and neutrons and is positively charged. The positively charged nucleus of the atom attracts and is circled by negatively charged electrons. This is because opposite charges attract each other while similar charges repel one another.
The positive charge of the protons is equal to the negative charge of the electrons despite an electron being only about 1/2000th the mass of a proton. When an atom is in balance, it has an equal number of protons and electrons. An atom becomes a negatively charged ion when it contains more electrons than protons and a positively charged ion when it contains more protons than electrons. The neutrons carry no charge and their number can vary.
The number of protons in an atom determines the kind of atom or element, it is. An element is a substance in which all of the atoms are identical. Atoms of one element all have the same number of protons but can have a different number of electrons and neutrons in which case they are called Isotopes.
Electrons usually remain at a constant distance from the nucleus in precise shells. The shell closest to the nucleus can hold up to two electrons. The second shell can hold up to eight. The third shell up to 18 and the outer shells can hold even more. Some atoms with many protons can have as many as seven shells with electrons in them. These shells are populated with electrons from the inside out. This means that any added electron will naturally fill in the innermost shells first before the outermost shell which is called the valence shell. The valence shell contains valence electrons and determines the reactivity of the atom. When the valance shell is full, the atom is usually stable and less reactive.
An example of this would be a hydrogen atom which contains only one proton and one electron. The positive charge of the proton and the negative charge of the electron balance each other out, which causes the electron to be tightly held by the proton in the nucleus of a hydrogen atom. Since the hydrogen atom is balanced perfectly, the electron cannot be removed easily from its orbit.
However, a copper atom contains 29 protons and 29 electrons which orbit the nucleus of the atom. Since the first 28 electrons occupy the first 3 shells, we have one electron left for the 4th outermost shell of the copper atom. This is called a free electron or a valence electron that can be easily removed from the copper atom due to its distance from the nucleus. Similarly, a silver atom contains 47 electrons which occupy 5 shells with the first 46 electrons in the first 4 shells leaving only one electron to orbit the 5th shell. The valance electron of the silver atom is further away from the center than the copper atom and is even easier to remove from its orbit since the force of attraction is not as strong there as it is in the closer shells.
Thus, the structure of an atom determines how easily an electron can be removed. Valence electrons that can be easily removed from their orbits are very important to the study of electricity. Now that we know that applying a force can make electrons move from one atom to another, we conclude that electricity is nothing more than just the flow of electrons.
We rely heavily on electricity in our daily lives but rarely do we think about what it actually is. Today we will discuss the basics of electricity and hopefully gain an appreciation for this wonderful source of energy at our disposal.
To understand the basics of electricity, we must first understand the basics of the atom. Everything in the universe is made of atoms. They are microscopic particles that make up all matter and are considered to be the building blocks of the universe. An atom is made up of even smaller particles called protons, neutrons, and electrons. Protons and electrons both carry an electrical charge which is a force within the particles. Protons have a positive charge while electrons have a negative charge. The positive charge is usually represented by a plus sign and the negative charge is represented by a minus sign. Neutrons do not have any charge and are therefore considered neutral. Atoms have a center known as the nucleus, which is made up of protons and neutrons and is positively charged. The positively charged nucleus of the atom attracts and is circled by negatively charged electrons. This is because opposite charges attract each other while similar charges repel one another.
The positive charge of the protons is equal to the negative charge of the electrons despite an electron being only about 1/2000th the mass of a proton. When an atom is in balance, it has an equal number of protons and electrons. An atom becomes a negatively charged ion when it contains more electrons than protons and a positively charged ion when it contains more protons than electrons. The neutrons carry no charge and their number can vary.
The number of protons in an atom determines the kind of atom or element, it is. An element is a substance in which all of the atoms are identical. Atoms of one element all have the same number of protons but can have a different number of electrons and neutrons in which case they are called Isotopes.
Electrons usually remain at a constant distance from the nucleus in precise shells. The shell closest to the nucleus can hold up to two electrons. The second shell can hold up to eight. The third shell up to 18 and the outer shells can hold even more. Some atoms with many protons can have as many as seven shells with electrons in them. These shells are populated with electrons from the inside out. This means that any added electron will naturally fill in the innermost shells first before the outermost shell which is called the valence shell. The valence shell contains valence electrons and determines the reactivity of the atom. When the valance shell is full, the atom is usually stable and less reactive.
An example of this would be a hydrogen atom which contains only one proton and one electron. The positive charge of the proton and the negative charge of the electron balance each other out, which causes the electron to be tightly held by the proton in the nucleus of a hydrogen atom. Since the hydrogen atom is balanced perfectly, the electron cannot be removed easily from its orbit.
However, a copper atom contains 29 protons and 29 electrons which orbit the nucleus of the atom. Since the first 28 electrons occupy the first 3 shells, we have one electron left for the 4th outermost shell of the copper atom. This is called a free electron or a valence electron that can be easily removed from the copper atom due to its distance from the nucleus. Similarly, a silver atom contains 47 electrons which occupy 5 shells with the first 46 electrons in the first 4 shells leaving only one electron to orbit the 5th shell. The valance electron of the silver atom is further away from the center than the copper atom and is even easier to remove from its orbit since the force of attraction is not as strong there as it is in the closer shells.
Thus, the structure of an atom determines how easily an electron can be removed. Valence electrons that can be easily removed from their orbits are very important to the study of electricity. Now that we know that applying a force can make electrons move from one atom to another, we conclude that electricity is nothing more than just the flow of electrons.
