250 likes | 438 Views
Organization of Matter. S1-2-03 Define element and identify symbols of some common elements. S1-2-06 Investigate the development of the periodic table as a method of organizing elements. S1-2-08 Relate the reactivity and stability of different families of elements to their atomic structure.
E N D
S1-2-03 Define element and identify symbols of some common elements. S1-2-06 Investigate the development of the periodic table as a method of organizing elements. S1-2-08 Relate the reactivity and stability of different families of elements to their atomic structure. Vocabulary & People Period Non-metals Group Family Alkali metals Earth metals Chalcogens Halogens Noble gases Mendeleev
Elemental symbols originated from a Greek or Latin root word
Mendeleev (1870) • Russian scientist and professor • Arranged the 63 elements by atomicmass • Noticed a repetition of properties (periodicity) • Called the patternof properties “Periodic Law” Mendeleev (correctly) predicted the mass of elements yet to be discovered and left spaces open for them
Moseley(1913) Experimentsshowed proton number was a better method to organize the elements. • Repetition of properties (periodicity) became more clear Modern 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
The Periodic Table contains metals and non-metals. A staircaseseparates metals from non-metals. M e t a l s Non- metals
Rows of the periodic table are called periods. • Elements in periods do nothave similar properties • Left to right • Elements change from metals tonon-metals Non-metal Element with properties opposite to those of metals (brittle, dull…) periods
Columns of the periodic table are called groups. • Elements in groups have similarproperties • A family is a group with a specific name: Family names and locations need to be memorized GROUP • Alkali metals • Alkaline Earth metals • Chalogens • Halogens • Inert (noble) gases
Older tables have an old label system for columns with Roman numerals – new tables just number them 1 through 18
Hydrogen* • Group 1 • Non-metal gas • 1 valence electron • Simplest atomic structure - only 1 e- and 1 p+ • Highly chemically reactive The 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
The Octet Rule of Chemical Reactions • Atoms with a FULL outer orbit are very stable Chemical reactions happen when atoms work together to try to get a fullvalenceorbit • Atoms will acquire a full outer shell in 3 ways: • Give away an e- to another atom • Take an e- from another atom • Share an e-with another atom We’ll skip this one until next year
+ Sodium atom: 11 p+ 11 e- Na Sodium ion: 11 p+ 10 e- Na + Once a neutralatom gains or loses e-to be more stable it is called an ion
- Chlorine atom: 17 p+ 17 e- Cl Chlorine ion: 17 p+ 18 e- Cl - Notice the ionhas a charge associated with it based on the number of e- lost or gained
2+ Calcium atom: 20 p+ 20 e- Ca Calcium ion: 20 p+ 18 e- Ca 2+
3- Nitrogen atom: 7 p+ 7 e- N Nitrogen ion: 7 p+ 10 e- N 3-
TheLESS electrons needed, theGREATERthechemical reactivity of the element Increasing Reactivity A Chemical Reaction Movement of electrons between combiningatoms that results in the formation of a NEW substance.
Working together to become more stableis what binds atoms (now called ions) together to make compounds. A new substance is formed - + explosive metal toxic gas Salt!
CAN YOU ANSWER THESE QUESTIONS? S1-2-06 How is the Periodic Table organized for the elements and what trends exist? S1-2-03 What are the symbols of the first 20 elements and other common ones? S1-2-08 Why do families react differently during chemical reactions? Vocabulary & People Non-metals Period Group Family Alkali metals Earth metals Chalcogens Halogens Noble gases Mendeleev