Subatomic Particles and their properties

725 Words3 Pages
Subatomic Particles and the periodic table 1. The three particles and their properties An atom has no overall charge. The protons (positively charged) and neutrons (no charge) make up the nucleus of an atom, and this is surrounded by negatively charged electrons. There are as many protons as electrons, so they balance each other out, creating a neutral relative charge on the atom. Neutrons, Protons and electrons are all sub-atomic particles. In relative mass, we always think of protons and neutrons in having a mass of 1 and electrons a mass of 1/1840, which shows that electrons are considerably smaller than protons and neutrons, and only make up a small part of the atom. The amount of protons and neutrons added together is the relative atomic mass, and this is the main structure of the atom. 2. The arrangement of particles in an atom Protons and neutrons make up the main, dense, central nucleus in the centre of the atom. This is surrounded by electrons “orbiting” the main nucleus. The electron are in shells depending on their energy levels, as the most energetic are on the outer shells, because they need more energy to travel around a bigger “orbit” of the nucleus. These shells are full when a certain amount of atoms are in the shell; 2 in the first shell, 8 in the next shell, 8 in the third shell and so on. When the shells are full, the atom is unreactive. 3. How the numbers of the different sub-atomic particles determine the properties of the atom and the position of the element of the periodic table. The main nucleus of an atom is made of protons and neutrons. These added together make the relative atomic mass. The mass number displayed on the periodic table, however, is only an average number, as there are many different isotopes if the same atom. The mass of the atom determines the weight of the atom, and the elements are ordered by the mass

More about Subatomic Particles and their properties

Open Document