2S1-2-03 Define element and identify symbols of some common elements. S Investigate the development of the periodic table as a method of organizing elements.S Relate the reactivity and stability of different families of elements to their atomic structure.Vocabulary & PeoplePeriod Non-metals GroupFamily Alkali metals Earth metalsChalcogens Halogens Noble gasesMendeleev
3Elemental symbols originated from a Greek or Latin root word Modern SymbolsAlchemist SymbolsDalton SymbolsAntimonySbArsenicAsBismuthBiCarbonCCopperCuGoldAuIronFeLeadPbMercuryHgSilverAgSulpherSTinSnZincZn
4Russian scientist and professor Mendeleev (1870)Russian scientist and professorArranged the 63 elements by atomic massNoticed a repetition of properties (periodicity)Called the pattern of properties “Periodic Law”Mendeleev (correctly) predicted the mass of elements yet to be discovered and left spaces open for them
5Repetition of properties (periodicity) became more clear Moseley (1913)Experiments showed proton number was a better method to organize the elements.Repetition of properties (periodicity) became more clearModern Periodic Law:“The properties of elements are a periodic function of increasing atomic number”We know now that most element properties are due to the number of valence electrons – luckily electron and proton numbers are equal
7M e t a l s The Periodic Table contains metals and non-metals. A staircase separates metals from non-metals.Non- metalsM e t a l s
8Element with properties opposite to those of metals (brittle, dull…) Rows of the periodic table are called periods.Elements in periods do not have similar propertiesLeft to rightElements change from metals to non-metalsNon-metalElement with properties opposite to those of metals (brittle, dull…)periods
9Family names and locations need to be memorized Columns of the periodic table are called groups.Elements in groups have similar propertiesA family is a group with a specific name:Family names and locations need to be memorizedGROUPAlkali metalsAlkaline Earth metalsChalogensHalogensInert (noble) gases
10Older tables have an old label system for columns with Roman numerals – new tables just number them 1 through 18
16Simplest atomic structure - only 1 e- and 1 p+ Hydrogen*Group 1Non-metal gas1 valence electronSimplest atomic structure - only 1 e- and 1 p+Highly chemically reactiveThe placement of hydrogen is only because of its structure - 1 proton… Sometimes a table will have it raised above the Alkali Metals to avoid confusion
18The Octet Rule of Chemical Reactions Atoms with a FULL outer orbit are very stableChemical reactions happen when atoms work together to try to get a full valence orbitAtoms will acquire a full outer shell in 3 ways:Give away an e- to another atomTake an e- from another atomShare an e- with another atomWe’ll skip this one until next year
19+ Sodium atom: Sodium ion: 11 p+ 11 p+ 11 e- 10 e- Na Na + Once a neutral atom gains or loses e- to be more stable it is called an ion
20- Chlorine atom: Chlorine ion: 17 p+ 17 p+ 17 e- 18 e- Cl Cl - Notice the ion has a charge associated with it based on the number of e- lost or gained
23Increasing Reactivity The LESS electrons needed, the GREATER the chemical reactivity of the elementIncreasing ReactivityA Chemical ReactionMovement of electrons between combining atoms that results in the formation of aNEW substance.
24A new substance is formed Working together to become more stable is what binds atoms (now called ions) together to make compounds.A new substance is formed-+explosive metaltoxic gasSalt!
25CAN YOU ANSWER THESE QUESTIONS? S1-2-06 How is the Periodic Table organized for the elements and what trends exist?S1-2-03What are the symbols of the first 20 elements and other common ones?S1-2-08Why do families react differently during chemical reactions?Vocabulary & PeopleNon-metals Period GroupFamily Alkali metals Earth metalsChalcogens Halogens Noble gasesMendeleev