To understand electricity, we must understand what makes it flow. Electricity is a form of energy. All matter is made up of atoms, and atoms have subatomic particles. There are three subatomic particles, which are protons, neutrons and electrons. The structure is such that the central part, known as the nucleus, contains the protons and neutrons, the electrons orbit around the nucleus. Protons in an atom have a positive charge and electrons have a negative charge. Neutrons in atoms have no charge. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get Original Essay The structure is such that the charge of the electrons and protons are attracted to each other and this keeps the electron in orbit around the nucleus. The number of neutrons and protons in an atom is the same; furthermore, the number of protons and electrons is the same. For example, the element hydrogen, the atomic number is 1; this means there is a neutron and a proton and therefore an electron. Atoms must have the same number of protons and electrons to be stable. When a charge is given to an atom, this causes the atoms to flow and pass onto another atom causing a flow of electrons. The charge will be known as the electromotive force needed to move the electrons. Conductivity is a critical part of making systems that allow electricity to flow through them and function. A conductor is a material that allows electricity to flow through it. This means that a conductive material will allow electrons to flow freely and therefore electricity will flow well. In the periodic table of elements we have a group of metals called transition metals, these are the materials that best allow electricity to flow through them. In figure 1 you can see the transition metals in the periodic table, highlighted in yellow. A semiconductor is a material that allows some electricity to pass through; these are useful because we can control the amount of electricity flowing through a part of a circuit. They are not conductive like normal conductors; however, they have their applications in electronics. An insulator is a material that has high resistivity; this means it allows little or no electricity to pass through it. Insulators are commonly used around cables to ensure they are safe to handle, this will ensure that people do not come into contact with live electricity. Insulators have fewer or no free electrons, meaning they are unable to pass energy through electron flow. Potential difference is defined as the potential difference between two points. This means that we observe the volts flowing through one point, and we observe the volts flowing through another point, and we use this to find out how strong the electron flow is. The potential difference is measured in volts. Current is a measure of how many electrons flow and this is measured in amperes. Electrons are so small that we need to increase the number of electrons flowing through a circuit; we use coulombs to measure the amount of electrons flowing through a point. One coulomb is 6.24*1018 There are two types of current flow, we have conventional current flow and electron flow. Conventional current flow is electrons flowing from the positive side to the negative side. This is what we first thought happened when electricity was discovered, but from tests and experiments we know that electrons flow from the negative side to the positive side, this is known as electron flow. There.