Presentation on theme: "Aim: How are Elements Organized in the Periodic Table?"— Presentation transcript:
1 Aim: How are Elements Organized in the Periodic Table? DO Now:1. How would you organize these buttons?2. How do you think elements are organized in the periodic table?3. Write at least one trend you notice about the elements in the periodic table.
2 History of the Periodic Table The first periodic table was developed in Russia in 1869 by chemist Dmtri Mendeleev; he arranged the elements in order of increasing atomic mass.The modern periodic law states: elements are arranged in order of increasing atomic numbers.Chemists use the properties of elements to sort them into groups.
3 Periods and Groups Periods Groups or Families Vertical columns Horizontal rowsThe # of the period indicates the # of energy levels (shells) in the elementThe # of valence electrons (electrons in outer shell) increases from right to leftProperties of elements change across a periodVertical columnsMost elements within the same group have the same number of valence electrons (electrons in outermost shell); therefore, have similar chemical properties
4 Three Classes of Elements MetalsAlkali MetalsAlkaline Earth MetalsTransition MetalsInner Transition MetalsMetalloidsNonmetalsHalogenNoble Gases
6 Metals vs Non Metals Properties Metals solids at room temperature are malleableare ductilehave lustergood conductors of heat and electricityProperties of Nonmetalsmany are gases at room temperaturenot malleable, tend to be brittle in the solid phase.surface is dullpoor conductors of heat and electricity
7 Metallic CharacterThe metallic character of an element can be defined as how readily an atom can lose an electron.Metallic characteristics decrease from left to right across a period, and increase down a group.
9 Alkali Metals and Alkaline Earth Metal Alkaline Earth MetalsGroup 1Most active metals in the periodic tableAll react vigorously with water to produce H2(g)They are shiny, have the consistency of clay, and are easily cut with a knife.Reactivity increases as you go down this periodGroup 2Second most active metals
11 Transition Metals and Inner Transition Metals The elements in Groups 3 through 12Typically hard solids with high melting points, with the exception of mercuryForm colored compounds.Are good conductors of heat and electricity.Can be hammered or bent into shape easily.(malleable)Are less reactive than alkali metals such as sodium.
13 MetalloidsThey can be found adjacent to the stair-step line in the periodic table.Have properties similar to those of metals and nonmetals.SolidsCan be shiny or dullDuctileMalleableConduct heat and electricity better than nonmetals but not as well as metals
14 Metalloids Cont.boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and polonium (Po) are the elements found along the step like line between metals and non-metals of the periodic table.
16 HalogensGroup 17Halogens have 7 valence electrons, which explains why they are the most active non-metalsHave low melting points and boiling pointsChemical reactivity decreases as you go down the group
18 Noble Gases Group 18 Colorless gases Do not chemically react with other elements (inert or stable)Are isolated atoms
19 ActivityGiven the blank periodic table fill in each category with a different color.Alkali Earth Metals Nonmetals2. Alkaline Earth Metals 7. Nobles Gases3. Transition Metals Metalloids4. Inner transition Metals 9. Other Metals5. Metalloids Halogens