Atomic Structure

Elements Atoms Components of an Atom Atomic Number Periodic Table of Elements Electrons Electron Orbits

Elements The simplest form of matter

Atoms The smallest piece of an element that contains all properties of that element

Components of an Atom Nucleus The center portion of an atom containing the protons and neutrons Protons Positively charged atomic particles Neutrons Uncharged atomic particles

Atomic Number The atomic number is equal to the number of protons in the nucleus of an atom. The atomic number identifies the element. What is the atomic number of this element?

Electrons For this unit, we mainly care about electrons in atoms. Why? It is important to understand the “how and why” of the movement of electrons to understand electricity.

Electrons Negatively charged particles

Electrons The electrons reside in the electron cloud The clouds are divided into 7 energy levels Electrons “reside” in lowest energy levels whenever possible.

Metals, Non-Metals, & Metalloids

Combination of metal and non-metal properties Conduct heat & electricity better than insulators, but not as good as metals Solids Semi-conductors Poor Conductors Good Insulators Dull Luster Brittle Low Density Melt at lower temps High Electronegativity Good Conductors Poor Insulators Shiny Malleable High Density Low Electronegativity

Semiconductors Include Carbon, Germanium, and Silicon Contain 4 valence electrons Neither a good insulator, nor a good conductor, but can be made a better conductor through doping. Needed for transistors and microchips Silicon is most often used in electronic applications Silicon is an insulator at room temperature but becomes a conductor when heated

Image Resources Microsoft, Inc. (2008). Clip Art. Retrieved September 10, 2008, from National Aeronautics and Space Administration (NASA). (n.d.). Genesis: Search for origins. Retrieved September 10, 2008, from html html