THINK SHARE What is matter? What do you think? What do you think? Matter Think – Pair - Share PAIR Individually, think of what you know about “matter”. This was part of your 6th grade science class. Write down what comes to mind when you think of “matter”. 5 - 7 minutes Now pair up with a partner (or team) and share your thoughts and ideas. One person serve are the recorder and put these on the construction paper. 5 – 7 minutes Each team will then share their information with the class. Tape the construction paper up for other students to see.
Matter: Properties and Change http://www.youtube.com/watch?v=FSyAehMdpyI “The Nucleus: Crash Course Introduction To Chemistry” #1” 10:12 Matter, is a substance that has mass and also volume. The volume is determined by the space it occupies, while the mass is defined as a measure of how much matter is in an object. http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/ size comparisons from milky way galaxy to quarks
Electricity Sunlight Water What is matter? Explain your reasoning.http://commons.wikimedia.org Smoke Earth’s Atmosphere Heat
Early alchemists thought that everything was made of either earth, air, water or fire.
“The Elements” VHS 50:52 http://youtu.be/zUDDiWtFtEM “The New Periodic Table Song 2:29 http://www.ncpublicschools.org/docs/accountability/testing/releasedforms/2009grade8periodic.pdf DPI periodic table
Chemistry Spoons Game The first letter is always capitalized. In symbols with two or more letters, only the first letter is capitalized. Element Information 73 An atom will have the same number of electrons as protons.
Coach Lesson #1 Atoms: most basic unit of matter; atoms make up everything Lithium atom (atomic #3 = protons) • An atom containing an equal number of protons (+) and electrons (-) is electrically neutral, otherwise it is positively or negatively charged and is known as an ion. An atom is classified according to the number of protons (atomic #): • the number of protons (atomic #) determines the chemical element, • and the number of neutrons determines the isotope of the element. ( i.e. carbon 12 and 14) Atomic Mass = 7 (protons and neutrons) Protons = positively charged Neutrons = neutral (no) charge Electrons = negatively charged What particles are in the nucleus?
How do sizes of atomic particles differ? • Electrons are extremely small compared to all of the other parts of the atom. • The mass of an electron is almost 1,000 times smaller than the mass of a proton. (Quarks make up protons and neutrons.)
How is the size of atomic particles measured? The nanometer is often used to express dimensions on an atomic scale: • The diameter of a helium atom, for example, is about 0.1 nm, and that of a ribosome is about 20 nm. Where are the protons and neutrons located? 2 (protons and neutrons)
How many valence electrons are shown in this atom? Electron Orbitals/ Cloud/Energy Level/Shell Configurations Valence electrons are those located in the outer most shell/level.
Atomic Structure of Helium 1. How many protons(+) are in helium? 2. How many neutrons (neutral) are in helium? How many electrons (-) are in helium? How many valence (outer level) electrons are shown?
Lithium • Protons = 3 (atomic number) • Neutrons = 4 • Mass Number/Weight = 7 (protons and neutrons) • Electrons = 3 * The number of protons (+) and electrons (-) will be the same. N Lithium (Li): One neutron is not shown. 1. What period is lithium in? 2. What group/familyis lithium in? 3. How many valence (outer) electrons does lithium have?
Elements above 92 are synthetic meaning they are “manmade” and not found in nature.
Atomic Structure of Carbon 1. How many protons (+) are shown? 2. What is the atomic mass? 3. How many neutrons (neutral) are shown? 4. How many electrons (-) are shown? 5. How many valence (outer level) electrons are shown?
Classifications of elements Some sources have astatine as a metalloid while others do not.
Atom Diagram Practice Name That Element
Atomic Structure of Boron “Build That Atom” Activity http://phet.colorado.edu/en/simulation/build-an-atom build an atom activity 1. How many protons (+) are shown? 2. How many neutrons (neutral) are shown? 3. How many electrons (-) are shown? 4. How many valence (outer level) electrons are shown? A. What is the atomic number of boron? B. What is the mass number of boron? C. What family is boron in? D. What group is boron in?
Helium only has 2 valence electrons. Why is it in group 18? Valence Electrons Why are the noble gasses the “happiest” elements? The valence is the number of outer shell/orbital electrons. These are the electrons available to take part in chemical reactions. The periodic trend for valence works well for the representative elements, which are in groups 1, 2, 13, 14, 15, 16, 17, and 18 (the ‘tall’ parts of the table). Reading left to right, the valence for each of the main groups increases from one to 8. The noble gas elements, with 8 valence electrons, are especially stable.
Periodic Table Color Coding Activity A group/family on the periodic table means the elements have similar chemical properties. Elements of the same period have the same number of electron orbitals/shells. Valence electrons can be determined by looking at the group/family. Group 1 = 1 valence (outer) electron Group 2 = 2 valence (outer) electrons Group 13 = 3 valence (outer) electrons, etc. (transition elements 3-12 will vary) Valence electrons are what determine the bonding ability of an atom.
Essential mineral elements : (elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules) nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum, and nickel. Beneficial elements: elements which promote plant growth in many plant species but are not absolutely necessary for completion of the plant life cycle : Silicon, sodium, cobalt, and selenium Essential nonmineral elements; (elements taken up as gas or water): hydrogen, oxygen, and carbon
Some sources show astatine as a metalloid while other do not. Metals, Nonmetals and Metalloids along zigzag line
Classifications of Elements Why is hydrogen not connected to group 1? Classifications of elements 34 Se Selenium 77 84 Po Polonium 209 Some periodic tables include astatine as a metalloid. Based on the site http://www.chemicalelements.com/groups/metalloids.html astatine is not a metalloid. http://www.chemtopics.com/elements.htm interactive periodic table
Metalloids 84 Po 85 jAt Metalloids are a chemical element with properties that are in-between or a mixture of those of metals and nonmetals. The seven elements commonly recognized as metalloids are boron, silicon, germanium, arsenic, antimony, polonium and tellurium. They or their compounds find uses in glasses, alloys or semiconductors. These are located along the zigzag line.
Group/Family 1 - 18 Period Metalloids: located along the zigzag lineThe seven elements commonly recognized as metalloids are boron, silicon, germanium, arsenic, antimony, polonium and tellurium. http://www.chem4kids.com/extras/quiz_elemintro/q02_no.html on-line quiz use periodic table
Notice that the metalloids and nonmetals are not included. Compare this section of the periodic table to the complete periodic table of elements. Metals
Metalloids & Nonmetals Some sources show astatine as a metalloid while other do not. Metalloids Nonmetals
Physical Properties: can be observed and measured without changing the kind of matter being studied; can be used to identify substances Melting Point: - The temperature at which a solid can change to a liquid. - The temperature at which a pure substance melts is unchanging under constant conditions. Boiling Point: - The temperature at which a liquid boils. - A substance changes from a liquid to a gas. - Boiling temperature is unchanging under constant conditions for a given substance. Density: - a property that describes the relationship between the mass of a material and its volume - Substances that have higher densities contain more matter in a given volume. - The density of a substance will stay constant/the same. Color: may be used to identify substances but not always Assessment Probe: “Floating Logs” Demo: Density Blocks Example: Man from Zambia
STC: “Finding the Conductor” 1.1 Physical Properties of Metals and Nonmetals
How are properties used to identify substances? H How are properties used to determine how elements and substances are used? Why is aluminum used in airplanes? Why is helium used in balloons instead of oxygen or hydrogen?
Example: Man from Zambia Chemical Property: any of a material's properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity Can be used to help identify a substance 2. Usually involves the substance’s ability to react or not react with another specific substance Examples Reacting with Oxygen (oxidation): The ability of a substance to burn is a chemical property that involves a substance reacting quickly with oxygen to produce light and heat. (i.e. iron rusts or apples turn brown). Reacting with Acids: The ability of a substance to react with an acid is a chemical property. Some metals react with various acids to form compounds. All metals do not react with all acids. Bases react with acids to form water and neutralize the acid.
Reactivity: the tendency of a substance to undergo chemical reaction, either by itself or with other materials.; reactivity is a chemical property of an element http://www.youtube.com/watch?v=Jy1DC6Euqj4 potassium reaction in water 20 sec. http://www.youtube.com/watch?v=MTcgo46nxNE sodium reaction in water 48 sec. These soft, silvery sodium chunks were cut with a knife and stored under oil. In air they turn white in seconds; exposed to water they generate hydrogen gas and explode in Flaming balls of molten sodium. http://www.youtube.com/watch?v=1bJBueGSC9M calcium reactivity with oxygen 27 sec.
Points to Consider If the property changes, is a new substance formed? If not, it is a physical property. If you still have the same substance after changing the property, it is a physical property. Physical or Chemical Property… What do you think? 1. Shape 2. Density 3. Acidity (below 7 pH) 4. Solubility 5. Basicity (above 7 pH) 6. Combustibility 7. Odor 8. Melting point 9. Reactivity 10. Boiling point 11. Color
Chemical vs Physical Changes (laptop review) Chemical Change: - properties change and a different substance is produced. - Chemical changes cannot be reversed. - Examples: iron reacts with oxygen and water to form iron oxide (rust); silver reacts with oxygen to form silver oxide (tarnish) Evidence of a chemical change: 1. Change in energy: temperature increase = exothermic chemical reaction temperature decrease = endothermic chemical reaction 2. Color change: This is not when a color has been covered, for example dying, painting, etc. 3. Formation of a gas: if in a solution, bubbles will often times been seen when the gas is formed 4. Formation of a precipitate: when two or more solutions are combined and a solid is formed STC: “The Burning Candle” 1.3 “Mixing the Solutions” 1.8 “Adding the Acid” 1.5
Physical Changes Physical Change: - The physical properties change but the type of substance stays the same. - matter changes is size, shape or form - There is no change in the chemical makeup of the substance(s) that are changed. - Physical changes can be reversed. - Examples: cutting, changes in states of matter (melting, boiling, freezing), etc. http://glencoe.mcgraw-hill.com/sites/dl/free/0078617650/160350/00044680.html Brain Pop Chemical and Physical Changes program w/quiz
Phase Change (mixing two or more substances) (dissolving a substance)
Sublimation: when a substance changes directly from a • gas to a solid • Examples: • The forming of frost from water vapor • When dry ice forms: Dry ice is frozen carbon dioxide. As it breaks down, it turns directly into carbon • dioxide gas rather than a liquid • http://www.youtube.com/watch?v=8tHOVVgGkpk • dry ice bubbles 2:20; also shows properties of polar • molecules water and detergent (surface tension) • Solid air fresheners Apples brown (react with oxygen)
Mini-Poster Analysis Is a phase change a physical or chemical change? Explain. What is the relationship between phase change and temperature? What effect does phase change have on the volume of the substance/molecules? Density? Mass? Explain. http://www.youtube.com/watch?v=czmQ2_ymaOo formation of ice crystals 37 sec.
Chemical Reaction: when a substance (or a few substances) change into another substance. STC: “Reacting A Tablet” 1.7 MRE Lab Endothermic Reactions = temperature decrease; Exothermic Reactions = Temperature increase A chemical change involves a physical change, and can include but is not limited to the following:Examples: change in color, texture, physical state, odor, production of a gas, formation of precipitate, a change in its solubility, burning, rusting, etc. Chemical changes do not change the mass, because according to the Law of Conservationof Mass/Matter, during a chemical reaction the mass of the reactants of the formula will always equal the mass of the products