Investigation 5 Experience 4 PDF

Investigation 5 Experience 4 Reminders Cell phones off & put away during class Request an e-hall pass before leaving the classroom No food/drinks (besides water) in the classroom  Click here to view the Agenda Word Wall Demo Analyz...

Investigation 5 Experience 4 Reminders Cell phones off & put away during class Request an e-hall pass before leaving the classroom No food/drinks (besides water) in the classroom  Click here to view the Agenda Word Wall Demo Analyze and Interpret Data Explain Skill Check 5.4 Demo How does aluminum foil compare with plastic wrap? Discuss with your table group: 1. How do the sheets tear differently? 2. How do the materials behave differently after being balled up? 3. Where have you seen metals bend, dent, or change shape? 4. How can you use what you learned in this demo to change the properties of a pure metal? What Are Polymers? Metallic Solids and Covalent Network Solids Click here to view the animation on SAVVAS. Analyze and Interpret Data The elements in the periodic table can be divided into metals and nonmetals. Metals have characteristic properties, such as being good conductors of heat and electricity and generally being strong, malleable, and ductile. Nonmetals tend to be brittle and are relatively poor conductors of heat and electricity. Figure 1 shows the melting and boiling points of some metals and nonmetals at standard pressure. Figure 2 shows their densities at standard temperature and pressure. Metals and Nonmetals: Data About Their Properties Element Density (g/cm3) lithium 0.53 magnesium 1.74 aluminum 2.7 gold 19.32 iron 7.874 mercury 13.543 oxygen 0.001429 silicon 2.07 helium 0.0001785 chlorine 0.003214 nitrogen 0.001251 bromine 3.12 Figure 1 Figure 2 Analyze and Interpret Data 1. Which of the elements shown are liquid at standard temperature and pressure? 2. Which of the elements shown are a gas at standard temperature and pressure? 3. Look at Figure 1. In general, do the nonmetals or metals have higher melting points? Note-taking Options  Comparing Metals and Nonmetals Copyright © Savvas Learning Company LLC. All Rights Reserved. Savvas is not responsible for any modifications made by end users to the content posted in its original format. Delocalized Electrons Metal atoms by themselves will not form a chemical bond with each other. When enough metal atoms come together, valence electrons from each metal atom can move around in the cluster. Eventually enough atoms come together to form a crystal structure. “Sea” of electrons Ductility and Malleability Metal Malleability is the ability to be hammered or pressed into shapes. Ductility is the ability to be drawn into wires. Cations can change positions without the bonds between them breaking because the sea of Ionic Compound electrons moves with the cations. Hammering an ionic compound would force the ions closer together causing them to repel each other and shatter. Conductivity and Luster Conductivity and luster are caused by the movement of free electrons. Light hitting the metal excites the free electrons which then re-emit the light causing the metal to look shiny. Metals have a high heat conductivity because electrons move heat energy as they travel through the metal. Metals are electrically conductive because the free electrons can flow as a current.  Crystalline Structure and Properties of Metals Metals are crystals with repeating structures. The type of crystal determines the bulk properties of the metal. FCC metals are the most ductile because they can be more tightly packed Face-centered cubic Body-centered cubic Hexagonal than BCC. (FCC) (BCC) close-packed HCP arrangements are (HCP) more brittle because they don’t have planes to slip across each other. Crystalline Structure and Properties of Metals Young’s Modulus is a measure of stiffness. Metals with a high ductility have a low Young’s Modulus. What pattern do you see with the structure? Defects and Properties of Metals Natural crystals often have defects. A point defect occurs at one point in the crystal lattice. Interstitial Substitution Vacancy Work Hardening Defects can create dislocations when propagated through a structure. A dislocation occurs when an entire plane is missing. The more dislocations in a metal, the lower its malleability. Swordsmiths hammer and fold metal blades to increase their strength. These actions create a dense network of dislocations throughout the metal structure, hardening the blade. Alloys An Alloy is mixture of metal atoms with Why are alloys made? one or more other types of atoms. They have different properties from pure metals due to defects created by the addition of other atoms. Some examples of alloys are steel, brass, bronze, and stainless steel. Checkpoint: Outer electrons are described as delocalized in metal substances. How can you describe the locations of these outer electrons in the electron clouds of individual atoms in the metal structure? Skill Check 5.4 Log onto Formative using your school account. Complete “Skill Check 5.4” independently and then work on Continuous Improvement. Skill Check is due by 11:59 PM.