Elements http://academic.brooklyn.cuny.edu/history/virtual/portrait.htm http://people.deas.harvard.edu/~jones/ap216/images/bandgap_engineering/periodic_table.gif

Elements, Compounds, and Mixtures What Do You Think? How is an element different from a compound?

Answer An element is made up of only one pure substance, and a compound is composed of two or more elements that are chemically combined. Gold http://www.worldofrockhounds.com/huge-gold-nugget-sm.JPG Water http://www.nbmg.unr.edu/slides/water/5.htm

Elements An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.

Elements A pure substance is a substance in which every particle of that element is the same. Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found. http://www.libertarian.nl/NL/archives/01-gold-bar.jpg

Every element has a unique set of properties. Elements Every element has a unique set of properties. The Periodic Table of Elements is arranged according to these properties.

Every element has a unique set of properties. Elements Every element has a unique set of properties. Some physical properties that are used to classify elements are boiling point, melting point, color, and density.

Elements Chemical properties used to separate elements from each other include reactivity with acids, or reactivity with oxygen.

Elements Are Grouped Some elements are shiny, and can conduct thermal energy. They are all grouped together on the left hand side of the Periodic Table. They are called metals. Not all metals are exactly alike, but they do have some properties in common.

Elements Elements Can Be Identified By Categories Try this! If you know the category, you know the properties. Try this! 1. Share with your class how CDs can be classified by categories? 2. How can dogs be classified by categories?

Elements are identified by 3 main categories Metals Nonmetals Metalloids Elements are identified by 3 main categories

Elements Metals Metals are elements that are usually shiny and good conductors of electricity and heat.

Metals are also malleable (can be hammered into thin sheets). Elements Metals Metals are also malleable (can be hammered into thin sheets).

Elements Metals are ductile, or can be drawn into thin wires. Metals are located to the left of the “zig zag line” on the Periodic Table.

Examples: Iron (Fe) and Copper (Cu). Elements Examples: Iron (Fe) and Copper (Cu). http://www.flamo.net/crystals/iron.jpg http://resourcescommittee.house.gov/subcommittees/emr/usgsweb/materials/copper.html

Click below to see properties of Metals. Elements Click below to see properties of Metals. http://www5.unitedstreaming.com/index.cfm

Elements Nonmetals Usually dull and poor conductors of heat and electric current. Tend to be brittle and unmalleable.

Elements Nonmetals Nonmetals are located to the right of the “zig zag line” on the Periodic Table.

www.neonstreet.com/ sign2.html Elements Nonmetals Examples: Neon (Ne) and Carbon (C) www.neonstreet.com/ sign2.html reluctant-messenger.com/ diamond_sutra.htm

Click below to see properties of Nonmetals Elements Click below to see properties of Nonmetals http://www5.unitedstreaming.com/index.cfm

Share properties of both metals and nonmetals. Can be shiny or dull. Elements Metalloids Share properties of both metals and nonmetals. Can be shiny or dull. Somewhat malleable and ductile.

Elements Metalloids touch the “zig zag line” on the Periodic Table. Examples: Silicon (Si) Arsenic (As).

Click below to see properties of metalloids. Elements Click below to see properties of metalloids. http://www5.unitedstreaming.com/index.cfm

Describe some physical properties of the element iron. Let’s Review! - 1 - Describe some physical properties of the element iron. http://neil.fraser.name/news/2004/05/22/

Physical properties include: Answer Physical properties include: Melting Point: 1535 °C Density: 7.9 g/cm3 Iron has the ability to conduct heat and electrical current.

Let’s Review - 2 - What is an example of a metal that is very malleable, shiny, and is used often in kitchens?

Answer Aluminum Foil

What do salt, sugar, baking soda, and water have in common? Compounds What Do You Think? What do salt, sugar, baking soda, and water have in common?

Compounds A compound is a pure substance composed of two or more elements that are chemically combined. Familiar Compound Compound Elements Combined Table Salt Sodium and Chlorine Water Hydrogen and Oxygen Sugar Carbon, Hydrogen, and Oxygen Carbon Dioxide Carbon and Oxygen Baking Soda Sodium, Hydrogen, Carbon, and Oxygen

Properties of Compounds Compounds, like elements, can be identified by their own physical and chemical properties. What are some examples of physical and chemical properties?

Compounds Each compound has different properties than the elements that make them up. Water Hydrogen Oxygen Melting Point 0°C -259.14 °C -218.4 °C Boiling Point 100 °C -252.87 °C -183.0 °C Density 1.0 g/cm3 0.08988 g/cm3 1.429 g/cm3 State at Room Temperature Liquid Gas

Compounds are Composed of Elements. The compound Water is composed of Hydrogen and Oxygen chemically bonded together.

Compounds Compounds are Composed of Elements. The compound Ammonium is composed of Nitrogen and Hydrogen chemically bonded together.

What is the difference between an element and a compound? Let’s Review! - 1 - What is the difference between an element and a compound?

Answer An element is a pure substance that cannot be separated into simpler means by physical or chemical means. A compound is a pure substance composed of two or more elements that can be broken into simpler substances by a chemical change.

Make a Venn diagram comparing and contrasting elements and compounds. Activity for Chapter 2 Elements Compounds

Elements, Compounds, and Mixtures Pre-AP Extensions for Chapter 2 Mixtures are combinations of two or more elements that are not chemically combined. Mixtures can be separated into 2 types: homogenous mixtures and heterogenous mixtures.

Elements, Compounds, and Mixtures Homogenous Mixtures A homogenous mixture is a mixture of two or more substances that is completely uniform in composition. Homogenous mixtures can be separated by physical means, but it is often difficult to do. Examples include salt water, kool aid, and air.

Elements, Compounds, and Mixtures Heterogenous Mixtures A heterogenous mixture consists of many different items, which are often not easily sorted or separated, though they are clearly distinct. Examples include oil and water mixed together, sand or gravel, and even chocolate chip cookies!

Elements, Compounds, and Mixtures Websites to Visit Percent Calculations in a Mixture Chromatography Mixtures Lab

Introduction to the Periodic Table What Do You Think? How do scientists use physical properties to arrange elements on the periodic table?

Introduction to the Periodic Table Dimitri Mendeleev discovered a pattern to the elements in the periodic table in 1869. www.astrosurf.org/lombry/ quantique-histoire.htm

Introduction to the Periodic Table He simply wrote the names of all of the elements on cards, along with some of their properties.

Introduction to the Periodic Table Mendeleev tried arranging his cards based on different properties like color, density, melting point, and atomic mass. He found that by arranging the elements by increasing atomic mass, he found many other properties that fit a pattern.

Introduction to the Periodic Table Mendeleev found that by arranging the elements by increasing atomic mass, similar physical and chemical properties repeated in every 8th element. This is called periodic, or having a regular, repeating pattern. Can you think of anything else that is periodic?

Why was Mendeleev so important in the study of the periodic table? Let’s Review! - 1 - Why was Mendeleev so important in the study of the periodic table?

Answer Mendeleev was responsible for arranging the periodic table by increasing atomic mass. This arrangement organizes the table making it easier for us to use.

Introduction to the Periodic Table What Do You Think? How do scientists use physical properties to arrange elements on the periodic table?

Introduction to the Periodic Table Elements are classified on the periodic table based on their properties. Like we learned in Chapter 2, we classify them as metals, nonmetals, and metalloids.

Introduction to the Periodic Table Metals Remember that metals are shiny, ductile, malleable, and are good conductors of thermal energy and electrical current. http://shawnee.noacsc.org/highschool/departments/teachers/pages/mikel/periodictable.html

Introduction to the Periodic Table Metals Metals are located to the left of the “zig zag” line on the periodic table.

Introduction to the Periodic Table Physical Properties of Metals Go.hrw.com

Introduction to the Periodic Table Chemical Properties of Metals Go.hrw.com

Introduction to the Periodic Table Nonmetals Remember also that nonmetals are not shiny and are poor conductors of thermal energy and electric current. http://shawnee.noacsc.org/highschool/departments/teachers/pages/mikel/periodictable.html

Introduction to the Periodic Table Nonmetals Nonmetals are found to the right of the “zig zag” line on the periodic table. http://shawnee.noacsc.org/highschool/departments/teachers/pages/mikel/periodictable.html

Introduction to the Periodic Table Physical and Chemical Properties of Nonmetals Go.hrw.com

Introduction to the Periodic Table Metalloids Metalloids are elements that have properties of both metals and nonmetals. http://shawnee.noacsc.org/highschool/departments/teachers/pages/mikel/periodictable.html

Introduction to the Periodic Table Metalloids Metalloids border the “zig zag” line on the periodic table.

Introduction to the Periodic Table Physical and Chemical Properties of Metalloids Go.hrw.com

Let’s Review! - 1 - Use the properties of metalloids to explain their position on the periodic table.

Answer Metalloids are located between metals and nonmetals because they have properties in between metal and nonmetals.