Atomic Structure Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Atomic Structure

Atomic Structure Elements Atoms Components of an Atom Atomic Number Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Atomic Structure Elements Atoms Components of an Atom Atomic Number Periodic Table of Elements Electrons Electron Orbits

Elements The simplest form of matter Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Elements The simplest form of matter Matter is the material from which all known physical objects are made. The image is of Beryllium, which has an atomic number of 4.

Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Atoms The smallest piece of an element that contains all properties of that element

Components of an Atom Nucleus Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? 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 How many protons are in this nucleus? Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Atomic Number The atomic number is equal to the number of protons in the nucleus of an atom. The atomic number identifies the element. How many protons are in this nucleus?

Periodic Table of Elements Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Periodic Table of Elements NASA Which element has 4 protons?

For this unit, we mainly care about electrons in atoms. Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? 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 Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons Negatively charged particles

Electrons 3D 2D Models of the Atom Bohr’s Model Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons Models of the Atom 3D 2D Bohr’s Model

Electrons The electrons reside in the electron cloud Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons The electrons reside in the electron cloud The clouds are divided into 7 energy levels Electrons “reside” in lowest energy levels whenever possible. Apartment Building Analogy The electron cloud is like an apartment building without an elevator. There are seven stories (energy levels). People will want to live on the lowest floor of the apartment building because its easier. The same is true with Electrons: they will want to “live” on the lowest energy level, because it is easier.

Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons Areas within each energy level where electrons move around the nucleus of an atom are known as Electron Orbitals. There are four different type of orbitals, each type able to contain different numbers of electrons Apartment Analogy Each apartment building has different types of apartments; studio apartments holding one or two people, one bedroom apartments which hold more people, two bedroom apartments which hold more than one bedroom apartments, and maybe even three bedroom apartments which hold the most. The same concept applies with electrons. Apartment: Each floor of the apartment building has different types of apartments where people live. Electrons: Each energy level has different types of orbitals where the electrons live. Sharp Principal Diffuse Fundamental

Electrons Types of Orbitals S orbitals can hold up to 2 electrons Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons Energy Level Types of Orbitals Maximum Electrons 1 (S) 2 (S & P) 8 3 (S, P, D) 18 4 (S, P, D & F) 32 5 6 7 Types of Orbitals S orbitals can hold up to 2 electrons P orbitals can hold up to 6 electrons D orbitals can hold up to 10 electrons F orbitals can hold up to 14 electrons Apartment Analogy Each floor of the apartment may have different types of apartments. Therefore, each floor of the apartment may hold different numbers of people. Each energy level of an atom may hold different numbers of electrons in its different types of orbitals.

Orbital Filling order: Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electrons Orbital Filling order: 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p Electrons will not completely fill all the orbitals in an energy level before moving up to another level. Because of this, There are never more than 8 electrons in the highest energy level! The electrons in the highest energy level of an atom are called the Valence Electrons Apartment Analogy People may move to a higher floor before lower floors become full. Electrons may “move” to a higher energy level before the lower levels are entirely full. Because of this there can never be more than 8 electrons in the highest energy level. Why???? This is a question best answered by college level chemistry and/or physics and beyond the scope of this course.

Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electron Orbits Atoms work to have their valence level either filled (8) or empty(0) of electrons. How many electrons are in the valence level? 1 Copper has a loose hold on this electron, so it can easily be moved It is easier for the copper atom to let go of one electron than it is to pick up 7 electrons to be full

Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electron Orbits Atoms like to have their valence level either filled (8) or empty(0) of electrons. How many electrons are in the valence level? 6 Sulfur has space to gain two electrons in its valence level. It is easier for the sulfur atom to pick up 2 electrons to be full, than to get rid of 6 electrons to be empty.

What does all this have to do with Electricity? Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? What does all this have to do with Electricity? The number of valence electrons in an atom will determine if an element will allow electricity to flow. The ability of an atom to draw electrons to itself (away from its neighbors) is called Electronegativity.

Conductors and Insulators Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Conductors and Insulators Conductors Insulators Electrons flow easily between atoms 1-3 valence electrons in outer orbit Low Electronegativity Good Conductors: Silver, Copper, Gold, Aluminum . . . Electron flow is difficult between atoms 5-8 valence electrons in outer orbit High Electronegativity Examples: Mica, Glass, Rubber, Plastic . . . Many examples of insulators are materials because atoms of one element have already bonded with atoms from other elements to make the materials very stable.

Conductors and Insulators Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Conductors and Insulators Identify conductors and insulators Insulators Conductors

Metals, Non-Metals, & Metalloids Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Metals, Non-Metals, & Metalloids

Metals, Non-Metals, & Metalloids Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Metals, Non-Metals, & Metalloids 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 Malleable – the ability to be shaped. Metals are generally good conductors because they have 1 or 2 valance electrons. Non-metals are good insulators because they have 5 or more valence electrons. Combination of metal and non-metal properties Conduct heat & electricity better than insulators, but not as good as metals Solids Semi-conductors

Semiconductors Include Carbon, Germanium, and Silicon Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? 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 Transistors and microchips are the heart of electronic devices. Doping is the process of adding impurities to increase conductivity. ***See the Teacher Notes for instructions on how to do a demonstration of doping.

Electron Flow in Conductors Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electron Flow in Conductors An atom will lose a valence electron when “pushed” by an electron from another atom. Conductors will easily lose electrons. The electrons can be knocked out of an atom into the next if enough force is applied.

Electricity Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Electron Flow Electricity is created as electrons collide and transfer from atom to atom. Play Animation

Atomic Structure Gateway To Technology® Unit 4 – Lesson 4.1 – What is Electricity? Image Resources Microsoft, Inc. (2008). Clip Art. Retrieved September 10, 2008, from http://office.microsoft.com/en-us/clipart/default.aspx National Aeronautics and Space Administration (NASA). (n.d.). Genesis: Search for origins. Retrieved September 10, 2008, from http://genesismission.jpl.nasa.gov/educate/scimodule/cosmic/ptable.html