The Periodic Table. run vertically on the periodic table (up and down).

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1 Lesson Objective: The Periodic Table Science 8.5B Interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements 8.2E Analyze data to formulate reasonable explanations, communicate valid conclusions supported by the data, and predict trends. Groups run vertically on the periodic table (up and down). are numbered Elements in the same have the same number of electrons in the outer energy level (with the exception of some transition metals). ed elements behave chemically in similar ways. GROUP 1: ALKALI Contains metals 1 Electron Reactivity: VERY Properties: solid, soft, react violently with water, shiny, low in density GROUPS 3-12 TRANSITION METALS Contains Commonly or valence electrons Less reactive than alkali or alkaline- metals

2 Properties: higher density and good conductors of heat and electricity GROUPS 3-13 TRANSITION METALS BELOW MAIN TABLES Contains the and Actinide Series These rows are pulled out and put below the main table to keep it from being too wide. Lanthanides are numbers -71. Actinides are numbers GROUPS 3-12 RARE EARTH ELEMENTS ~ LANTHANIDES follow transition metal #57, Lanthanum in Period 6 Commonly have 3 Valence VERY reactive : high luster, but tarnish easily; high conductivity for ; very small differences between them GROUPS 3-12 RARE EARTH ELEMENTS ~ ACTINIDES follow the transition metal #89, Actinium in period 7 Commonly 3 valence, but up to 6 Unstable o All are radioactive o Most are made in.

3 METALLOIDS A - line separate metals from metalloids Elements from contain some metalloids these elements have characteristics of and non-metals GROUP 13: The Boron Group Contains 1 metalloid and 4 3 valence Reactive Solid at room GROUP 14: The Carbon Group Contains 1 non-, 2, metalloids, and 3 4 valence Reactivity varies Solid at room GROUP 15: The Nitrogen Group Contains 2 non-, 2 metalloids, and 1 5 valence Reactivity varies All but N are solid at room GROUP 16: The Oxygen Group Contains 3 non-, 1 metalloid, and 2 6 valence Reactive All but O are solid at room temperature

4 GROUP 17: Halogens Contains non- 7 valence Very reactive Poor conductors of electric current Reacts violently with alkali metals to salts Never found uncombined in GROUP 18: Noble Gases Contains non- 8 valence electrons (2 for He) Unreactive (least reactive group) Colorless, odorless gases at room temperature Outermost energy full All found in the atmosphere HYDROGEN STANDS APART! H is set apart. Its properties do not match any single group. 1 valence. Very reactive, but loses or shares 1 easily. Similar to those of non- metals rather than metals. PERIODS run horizontally across the periodic table. are numbered 1-7. All elements in a will have the same number of energy levels, which contain electrons. Examples: o 1 atoms have 1 energy level. o 2 atoms have 2 energy levels.

5 Notes for OLS 9.1 Chemical Bonding The of any substance depends on the arrangement of types of atoms that are bonded together. The properties of compounds and the properties of the elements that the compounds contain are different. In a water molecule, H2O, hydrogen atoms form bonds with oxygen atom. Salt is called SODIUM CHLORIDE (NaCl). 1 atom sodium (Na) for every of chloride (Cl). The properties of table salt are different than sodium or chloride by themselves. Electrons in Bonding combine to form stable electron arrangements, Called compounds. Look at sodium and chloride. Sodium loses an electron to chlorine, creating a complete valence shell for both. Bonding When an gains or loses one or more electrons, an ION is formed. An ion has a charge. In NaCl, both Na and have a charge. The plus sign says the sodium has lost an electron. The negative sign means the chlorine has an electron (remember. It is backwards because electrons have a negative charge. IONIC BONDS form when oppositely charged ions attract. Salt is therefore an compound.

6 Nonmetals form a bond called a COVALENT BOND. COVALENT BONDS form when share one or more PAIRS of to get to eight electrons in their valence shell to make a molecule. Notes for OLS 9.2 Chemical Reaction REACTANTS are compounds whose bonds are broken then form different compounds called PRODUCTS. REACTANTS, ENERGY, and PRODUCTS are part of all reactions. EXOTHERMIC REACTION Exothermic reactions release energy. REACTANTS need energy to react (a spark to get it going). During the, HEAT AND LIGHT are formed and released. It is called because it releases more energy than is needed to start the reaction. ENDOTHERMIC REACTION

7 reactions need energy to keep the reactions going. These reactions become colder. Science COMBUSTION REACTION reactions is an exothermic in which oxides are (usually) formed, meaning one of the products is a something oxide like carbon dioxide. We get energy from fuels as a result of reactions. DECOMPOSITION REACTIONS reactions are reactions where compounds are down into 2 or more simpler compounds. Ex. H2O H H2O (water) is the reactant H are the products FORMING A PRECIPITATE A PRECIPITATE is a solid that forms as a result of a chemical.

8 OLS 9.3 Chemical Formulas IONIC BONDS are formed from the electrical attraction of oppositely charged ions. One transfers electrons to another atom. Ex. Table salt NaCl COVALENT BONDS form when share pairs of electrons. Ex. Carbon dioxide (CO) IONIC COMPOUNDS are electrically or neutral with a charge of 0. For a COVALENT COMPOUND, the chemical shows how many atoms of each kind join together to form the molecules of the compound. (also called a molecular formula) Writing CHEMICAL EQUATIONS describes a reaction using symbols and numbers. Ex. C + O (reactant) = CO (product) Remember, a small number after a means there are 2 of that atom. Ex. H2O means 2 atoms of Hydrogen and 1 atom of Oxygen