3.01 Elements, Symbols and Periodic Table

Transcription

1 .0 Elements, Symbols and Periodic Table Dr. Fred O. Garces Chemistry 00 Miramar College.0 Elements, symbols and the Periodic Table January 0

2 The Elements: Building block of Matter The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 89 by the Russian chemist Dmitri Mendeleev. Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as many new elements have been discovered, and new theoretical models have been developed to explain chemical behavior. Groups A group, also known as a family, is a vertical column in the periodic table of the elements. Groups are considered the most important way of classifying the elements. In some groups, the elements have very similar properties and exhibit a clear trend in properties down the group these groups tend to be given trivial (non-scientific) names, e.g. the alkali metals, halogens and noble gases. Some other groups in the periodic table display fewer similarities and/or vertical trends (for example Groups and ). Modern quantum mechanical theories of atomic structure explain that elements within the same group have the same electron configurations in their valence shell, which is the largest factor in accounting for their similar chemical properties. Periods A period is a horizontal row in the periodic table of the elements. Although groups are the most common way of classifying elements, there are some regions of the period table where the horizontal trends and similarities in properties are more significant than vertical group trends. This can be true in the d-block (or "transition metals"), and especially for the f-block, where the lanthanoids and actinoids form two substantial horizontal series of elements..0 Elements, symbols and the Periodic Table January 0

3 Elemental Symbols Chemical Elements: A chemical element, or element for short, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Common examples of elements are hydrogen, nitrogen, and carbon. In total, 8 elements have been observed as of 00, of which 98 occur naturally on Earth. Elements with atomic numbers greater than 8 (i.e., bismuth and those above), are inherently unstable and undergo radioactive decay. In addition, elements and (technetium and promethium) have no stable isotopes, and also decay. The decay is so long however it has yet to be determined experimentally. However, even the elements up to atomic number 9 with no stable nuclei are nevertheless found in nature, as a result of the natural decay processes of uranium and thorium. More expensive than gold Three forms Tarnish Tarnishsilver silver Main source from meteor.0 Elements, symbols and the Periodic Table January 0

4 Dmitri Mendeleev (89) In 89 Mendeleev and Lothar Meyer (Germany) published nearly identical classification schemes for elements known to date. The periodic table is base on the similarity of properties and reactivities exhibited by certain elements. Later, Henri Moseley ( England, 88-9) established that each elements has a unique atomic number, which is how the current periodic table is organized. Elements, symbols and the Periodic Table January 0

5 January 0.0 Elements, symbols and the Periodic Table The Periodic Table A map of the building block of matter. IA 8 VIIIA H.009 IIA Periodic Table IIIA IVA VA VIA VIIA He.00 Li.99 Be 9.0 B 0.8 C.0 N.00 8 O F Ne 0.9 Na.9898 Mg.0 IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB Al.98 Si 8.08 P 0.98 S.0 Cl. 8 Ar K Ca 0.08 Sc.9 Ti.90 V 0.9 Cr.99 Mn.980 Fe.8 Co Ni 8. 9 Cu. 0 Zn. Ga. Ge.9 As.9 Se 8.9 Br Kr 8.80 Rb 8. 8 Sr 8. 9 Y Zr 9. Nb 9.90 Mo 9.9 Tc [99] Ru 0.0 Rh 0.90 Pd 0. Ag Cd.0 9 In.8 0 Sn 8.9 Sb. Te.0 I.90 Xe.0 Cs.90 Ba. La 8.9 Hf 8.9 Ta W 8.8 Re 8. Os 90. Ir 9. 8 Pt Au Hg Tl 0. 8 Pb Bi Po [0] 8 At [0] 8 Rn [] 8 Fr [] 88 Ra [] 89 Ac [] 0 Ku [0]

6 Periodic Table Expanded View The way the periodic table is usually presented is a compressed view, placing the Lanthanides and Actinides at the bottom of the stable. The Periodic Table can be arrange by subshells. The s-block is Group IA and & IIA, the p-block is Group IIIA - VIIIA. The d-block is the transition metals, and the f-block are the Lanthanides and Actinide metals.0 Elements, symbols and the Periodic Table January 0

7 Periodic Table: Metallic arrangement Layout of the Periodic Table: Metals vs. nonmetals IA IIA IIIA IVA VA VIA VIIA 8 VIIIA IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB Metals Nonmetals.0 Elements, symbols and the Periodic Table January 0

8 Periodic Table: The three broad Classes Main, Transition, Rare Earth Atomic number Element symbol Atomic mass Main (Representative) and Transition metals 8.0 Elements, symbols and the Periodic Table January 0

9 Reading the Periodic Table: Classification Nonmetals, Metals, Metalloids, Noble gases 9.0 Elements, symbols and the Periodic Table January 0

10 Across the Periodic Table Periods: Are arranged horizontally across the periodic table (rows -) These elements have the same number of valence shells. IA IIA nd Period IIIA IVA VA VIA VIIA 8 VIIIA IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB th Period 0.0 Elements, symbols and the Periodic Table January 0

11 Down the Periodic Table Family: Are arranged vertically down the periodic table (columns or group, - 8 or -8 A,B) These elements have the same number electrons in the outer most shells, the valence shell. IA IIA Alkali Family: e- in the valence shell IIIA IVA VA VIA VIIA 8 VIIIA IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB Halogen Family: e- in the valence shell.0 Elements, symbols and the Periodic Table January 0

12 Infamous Families of the Periodic Table IA Notable families of the Periodic Table and some important members: Alkali IIA Alkaline (earth) Transition Metals IIIA Noble Gas Halogen Chalcogens IVA VA VIA VIIA 8 VIIIA IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB.0 Elements, symbols and the Periodic Table January 0

13 Important members - the Elements Individual members of selected Elements & their characteristics IA H IIA IIIA IVA VA VIA VIIA 8 VIIIA He Li B C N O F Na Mg IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB Al Si P S Cl K Ca V Cr Mn Fe Co Cu Zn Ge Se Br Mo I Elements, symbols and the Periodic Table January 0

14 Periodic Table: electron behavior The periodic table can be classified by the behavior of their electrons W e s t ( S o u t h ) M i d - p l a i n s E a s t ( N o r t h ) M E T A L S M E T A L L O I D N O N - M E T A L S A l k a l i N o b l e g a s A l k a l i n e H a l o g e n s T r a n s i t i o n C a l c o g e n s T h e s e e l e m e n t s T h e s e e l e m e n t s T h e s e e l e m e n t s t e n d t o g i v e u p w i l l g i v e u p e - o r t e n d t o a c c e p t e - a n d f o r m a c c e p t e - e - a n d f o r m IA IIA C A T I O N S A N I O N S IIIA IVA VA VIA VIIA 8 VIIIA IIIB IVB VB VIB VIIB 8 9 VIIIB 0 IB IIB.0 Elements, symbols and the Periodic Table January 0