What Are Elements?

Elements An element is a substance that cannot be broken down into simpler substances by physical or chemical means 92 elements occur naturally on earth and in stars Others are produced in labs Each element has it’s own symbol Ex.) H stands for hydrogen

Chemical Symbol Atomic Number Atomic Mass

Elements are Made of Atoms Particle Where found Charge Mass Electron Outside nucleus negative Hardly any Proton In nucleus positive 1 Neutron neutral An atom is the smallest particle of an element that has all of it’s characteristics of that element Atoms consist of even smaller parts Proton, neutron, and electrons A nucleus of an atom is made up of protons and neutrons

Equations The number of protons in an atom’s nucleus is the atomic number # of protons + # of neutrons = mass number Atoms have a neutral charge because they have the same number of electrons and protons