Periodic Table Notes (Quick Reference)

Transcription

1 Periodic Table Notes (Quick Reference) Periodic Trends: P.T. trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its size and its electronic properties such as: Atomic Radius:_ _ Size of an atom_ Electronegativity: an electron s ability to attract an atom Electron Affinity: energy released when an electron is picked up by an atom Ionization Energy: Energy required to remove an electron from an atom Note: Valance Electrons influence the trends. PERIODIC TABLE IONS:_ _Charged atoms Are positive and negative ions larger or smaller than their neutral states? Li if LOSE one negative electron then becomes larger/ smaller Li + F if GAIN one negative electron then becomes larger /smaller F - Cations are _positive ions which means they lose electrons and therefore they are _ smaller then their atoms. Cations: Metals that tend to lose electron and become cation (positive) Anions are _negative ions which means they _gain electrons and therefore they are larger _then their atoms. Anions: Nonmetals that tend to gain electron and become anion (negative) 1

2 Oxidation #: the charge of ion_. Valence Electrons: Electrons in the outermost energy level of an atom. Important because: They are used in bonding with other atoms Show chemical properties of an element Can be related to an element s position on the PT. Octet Rule: Atoms always try to reach stability by having a full_ _ shell_. When outermost shell is filled with _8_ electrons ( like Noble gases ) it s considered full. Label the PT & classify the properties of groups(below boxes). Hydrogen single proton and a single electron, simplest and most abundant element in the universe. 'burn' to produce energy. combines with other elements to form numerous compounds. 2

3 Ex: water (H 2 O), ammonia (NH 3 ), methane (CH 4 ), table sugar (C 12 H 22 O 11 ), hydrogen peroxide (H 2 O 2 ) and hydrochloric acid (HCl) Alkali Metals always 1+ (lose the electron in s subshell) strong metals unusually soft, silverish color, tarnishes(dull) quickly in air Very reactive toward Oxygen forming Oxides of the metal Alkali Earth Metals always 2+ (lose both electrons in s subshell) Not as soft as Group 1 metals. Shiny, crystaline. react more mildly with Oxygen to produce oxides of the metals Only react with water at temperatures where the water is steam. Transition Metals 2+ is common, and 1+ and 3+ observed Not as predictable Ductile, malleable, solids (except Mercury) Conductors of Electricity "Shielding effect" = More electrons between the valence outer electrons and the nucleus. These inner electrons will shield the valence electrons from the attractive influence of the positive nucleus. Therefore the distance factor is the dominate factor and the energy requirement for removing a valence electron decreases. Metalloids between metals and nonmetals Sometimes lose and sometimes gain electrons Ex: Si appears lustrous, is brittle, not malleable or ductile. Poorer conductor of heat and electricity than metals. Useful in the semiconductor industry. Seven are diatomic molecules : (HOClBrIFN = Huckleberry Finn!) Bromine(Br 2 ), Iodine(I 2 ), Nitrogen(N 2 ), Chlorine(Cl 2 ), Hydrogen (H 2 ), Oxygen(O 2 ), & Fluorine(F 2 ). 3

4 Halogens None metals, very reactive Produce Sodium salts Gases Noble Gases Noble gas group (inert gas group). Only a handful of compounds (mostly involving Xenon) Non reactive Full (8 valence electrons ) outermost shell. Actinides & Lanthanides Special inner transition state metals first rearranged by Dr. Glen Seaborg of Univ. of Calif. at Berkeley in the 1950's. Seemed to predict the properties of several newly synthesized man-made elements. Bohr Model of Oxygen Atomic Weight: 16_ Atomic #: 8_ _ P + = 8 e - = 8_ n 0 = 8_ _ Lewis Dot Structure Ionic Lewis Dot Structure Li Be B N O 4

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