Science Lesson About Atoms

Atoms Explanation of atoms and elements: Atom - An atom is the smallest particle of an element that still has the chemical properties of that element. - Atoms are composed of a positively charged atomic nucleus and negatively charged electrons. - The atomic nucleus consists of protons and neutrons. - The number of protons determines the atomic number or type of element. - The number of electrons is equal to the number of protons in a neutral atom. - Electrons orbit the atomic nucleus in electron shells. Element - Elements are pure substances that cannot be broken down into other substances. - Consists of one type of atom with the same number of protons. - Grouped in the periodic table of elements based on atomic number. - There are 118 elements that have been discovered, from metals, non-metals, metalloids and noble gases. - Elements have specific chemical properties such as electronegativity, electron affinity, and others. - Can form compounds with other elements. So atoms are the basic units that make up elements, and elements are types of atoms with certain chemical properties that can form compounds or mixtures. The following are examples of questions and explanations about atoms: Question: A neutral atom has 17 electrons and 20 neutrons. Define: a) Number of protons b) Atomic number c) Element symbols Explanation: a) The number of protons in a neutral atom is the same as the number of electrons, namely 17 b) The atomic number is determined by the number of protons, namely 17 c) Based on atomic number 17, this atom is the element Chlorine (Cl). Explanation: - Neutral atoms have the same number of protons as electrons so their charge is neutral. - The number of protons indicates the atomic number of the element - The atomic number determines the symbol and name of the element according to the periodic table of elements. - The number of neutrons does not affect the type of element, only the atomic mass. By knowing the composition of atoms (protons, electrons, neutrons) we can determine elements and their properties. This is the basic concept of atomic structure in chemistry.