Section II Basic Building Materials Lesson 6 A

Section II: Basic Building Materials Lesson 6 A New Language Lesson 7 Now You See It Lesson 8 What Goes Around Comes Around Lesson 9 Create a Table Lesson 10 Breaking the Code

Lesson 6: A New Language Chemical Names and Symbols

Chem. Catalyst Two bottles are on a shelf in a chemistry lab. Both contain a shiny yellow metal. Bottle A is labeled Au(s). Bottle B is labeled Fe. S 2(s). 1. What do you think the symbols on the bottles mean? 2. Do you think both bottles contain gold? Why or why not?

Key Question What do chemical names and symbols tell you about matter?

You will be able to: • • • define the terms element, compound, and aqueous recognize whether a substance is an element or a compound based on its chemical formula or symbol decipher some basic chemical formulas and symbols

Prepare for the Activity Work in groups of eight.

Discussion Notes The Language of Chemistry Symbol for sulfur Symbol for copper Symbol for oxygen Subscript for oxygen

Discussion Notes (cont. ) All matter in the universe either is an element or is made of some combination of elements. Element: A unique substance that cannot be broken down into simpler substances through chemical processes. Elements serve as the building materials of all matter. Compound: A pure substance that is a chemical combination of two or more elements in a fixed ratio.

Discussion Notes (cont. ) The first letter of an element’s symbol is always uppercase, and if there is a second letter it is always lowercase. Compounds are represented by chemical formulas. Chemical formula: A combination of symbols and subscripts that indicates the number and types of elements in a compound.

Discussion Notes (cont. ) Some common groupings of elements have their own specific names. Substances come in different physical forms, called phases. Phase: The physical form a substance is in, such as solid, liquid, or gas. Phase is greatly influenced by temperature. Aqueous: A substance is aqueous when it is dissolved in water.

Wrap Up What do chemical names and symbols tell you about matter? • Chemical symbols represent the elements. Each element has either a one- or two-letter symbol. The first letter is always uppercase; the second letter is always lowercase. • The chemical formula of a substance indicates what elements are in it as well as the relative amounts of each element in that substance. • The symbols (s), (l), (g), and (aq) indicate the physical form or phase of a substance and whether it is dissolved in water.

Check-in Imagine that you find a vial labeled Na 2 SO 4(aq). What does the label tell you about what is in this vial?

Lesson 7: Now You See It The Copper Cycle

Chem. Catalyst Answer these safety questions about the lab you will be doing today. If you can’t answer these questions, go back and reread the procedure. 1. Name three things that could be dangerous in this lab. 2. Why must part of the lab be done in a fume hood? 3. What do you need to put on before starting the lab? Why?

Key Question What happens to matter when it is changed?

You will be able to: • • follow a lab procedure safely describe a chemical change or chemical reaction

Prepare for the Lab Work in groups of four.

Prepare for the Lab (cont. ) During the lab, follow these safety guidelines: • Wear your safety goggles at all times. • Be very careful when handling chemicals. If any gets on your skin, wash the area immediately with water and inform your teacher. • Use the fume hood when adding the nitric acid to the copper; do not breathe in any of the gas. • When using the hot plate, set it at a medium setting. Be careful not to splash when stirring the chemicals.

Prepare for the Lab (cont. ) Remove the beaker from the hot plate with beaker tongs.

Prepare for the Lab (cont. ) Set up and use the funnel and filter paper following the instructions.

Check-in You could see copper only in the first and last steps of today’s lab. Where do you think the copper was the rest of the time? Be specific.

Lesson 8: What Goes Around Comes Around Conservation of Matter

Chem. Catalyst What do you think happened to the copper powder in the copper cycle experiment when it was mixed with the nitric acid?

Key Question What happens to elements in a chemical change?

You will be able to: • explain that the product of chemical reactions depends on what was present at the time of reaction • explain that matter cannot be created or destroyed in a chemical reaction

Prepare for the Activity Work in groups of four.

Discussion Notes The Copper Cycle

Discussion Notes (cont. ) You could prove that copper was not destroyed by measuring the mass of the copper powder at the beginning and at the end of the experiment. Law of conservation of mass: The law states that mass cannot be gained or lost in a chemical reaction–matter cannot be created or destroyed.

Discussion Notes (cont. ) No matter what was done to the copper, it was not broken down any further. The observations we have made in the copper cycle lab provide further evidence that the golden penny is not gold.

Wrap Up What happens to elements in a chemical change? • Elemental copper can be transformed through chemical reactions and then recovered. • We can represent elements with symbols and keep track of them during chemical reactions. • Elements combine and recombine but are not created or destroyed in chemical reactions.

Check-in Sodium chloride, Na. Cl (aq), is added to silver nitrate, Ag. NO 3 (aq), resulting in Na. NO 3 (aq) and a white solid. Identify the white solid from the list below. Explain your choice. A. Ag. Cl (s) B. Ag. Cl (aq) C. Ag. NO 3(s) D. Na. Cl (s)

Lesson 9: Create A Table Properties of the Elements

Chem. Catalyst 1. How do you think the elements are organized in this table? 2. What do you think the numbers represent?

Key Question How is the periodic table organized?

You will be able to: • describe how the organization of the periodic table is based on reactivity and atomic mass • predict the characteristics of a missing element on the periodic table based on its position in the table

Prepare for the Activity Work in groups of four with one set of Create a Table cards for each group.

Prepare for the Activity (cont. ) Atomic Mass: The mass of a single atom (or isotope) of an element. Each element has an average atomic mass that is expressed as a decimal number. These are the numbers that appear in the Chem. Cataylst and also on the Create a Table cards.

Prepare for the Activity (cont. ) What is reactivity? Reactivity is a property that describes whether an element or compound will chemically combine with other substances to form compounds and also describes the speed of a reaction. Reactivity information is included on the Create a Table cards.

Discussion Notes Mendeleyev organized his periodic table based on the properties of the elements, such as reactivity and atomic mass. Mendeleyev’s arrangement of the elements helped predict the existence and properties of as-yetundiscovered elements.

Wrap Up How is the periodic table organized? • Mendeleyev organized his periodic table based on the properties of the elements, specifically, reactivity and atomic mass. • Elements in each column of the periodic table have similar properties. • Reactivity describes whether an element will chemically combine with other common substances and also describes the speed of the reaction. • Mendeleyev’s arrangement of the elements helped predict the existence of undiscovered elements.

Check-in Which of these elements would be grouped �together on the periodic table? Explain your thinking. cadmium Cd moderately soft, silvery, solid, metal reacts very slowly with water found in Cd. Cl 2(s) zinc Zn moderately hard, silvery, solid, metal reacts very slowly with water found in Zn. Cl 2(s) iodine I purple, solid, nonmetal reacts slowly with metals found in ICl(s) mercury Hg silvery, liquid, metal does not react with water found in Hg. Cl 2(s)

Lesson 10: Breaking the Code The Periodic Table

Chem. Catalyst The atomic mass of silver is 107. 9 amu. The atomic mass of gold is 197. 0 amu. Where would you place these elements on the periodic table you created in Lesson 9: Create a Table? Explain your reasoning.

Key Question What information does the periodic table reveal about the elements?

You will be able to: • use the periodic table to identify elements that are metals, nonmetals, metalloids, alkali metals, alkaline earth metals, transition elements, halogens, noble gasses, lanthanides, and actinides • describe the general properties of elements, that are periodic in nature • predict the general properties of an element based on its location on the periodic table and identify elements that will exhibit similar chemical behavior

Prepare for the Activity In groups of four, sort the Create a Table cards using the patterns you discovered in Lesson 9: Create a Table.

Prepare for the Activity (cont. ) Open up the card sort.

Prepare for the Activity (cont. ) The card sort table can be opened up to accommodate more elements.

Prepare for the Activity (cont. ) Evolution of the Periodic Table

Prepare for the Activity (cont. ) Add Mendeleyev’s remaining elements.

Prepare for the Activity (cont. ) Atomic Number: The consecutive whole numbers associated with the elements on the periodic table. The atomic number is equal to the number of protons in the atomic nucleus of an element.

Discussion Notes There are horizontal (from left to right) and vertical (from top to bottom) patterns on the periodic table. Grainy shading indicates nonmetals and metalloids, solid shading indicates metals. Darker hues mean more reactivity. A black outline indicates solids, a red outline indicates gases, and a green outline indicates liquids.

Discussion Notes (cont. ) Vocabulary Related to the Periodic Table Group: A vertical column in the periodic table. Elements in a group have similar properties. Period: Horizontal rows on the periodic table. Alkali metals: The elements in Group 1 A. Alkaline earth metals: The elements in Group 2 A. Halogens: The elements in Group 7 A. Noble gases: The elements in Group 8 A. They are called “noble” gases because they are not reactive.

Discussion Notes (cont. ) Main group elements: The elements in Groups 1 A to 8 A. Transition elements: The elements in Groups 1 B to 8 B. Lanthanides and actinides: The two rows of 14 elements each that are placed separately at the bottom of the periodic table.

Discussion Notes (cont. ) Metals: Elements that are excelled conductors of heat and electricity. They generally are shiny and malleable (flexible). They are found to the left of the stair-step line on the periodic table. Nonmetals: Elements that are poor conductors of heat and electricity. They generally are dull and brittle. They are found to the right of the stair-step line. Metalloids: The elements between the metals and nonmetals. They are found along the stair-step line.

Wrap Up What information does the periodic table reveal about the elements? • Patterns repeat on the periodic table. The table is organized so elements in each column of the periodic table have similar properties. • The periodic table lists the name, symbol, and average atomic mass of each element. • Several groups of elements and some periods have specific names, such as halogens or noble gasses. • Metals are in the center and left, and nonmetals are at the top right; elements near the dividing line are considered metalloids.

Check-in Look up silver, Ag, on your periodic table. Use these cards for Cu, copper, and Au, gold, to create a card for silver.