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Periodic Table. Trends. Trends of the Periodic Table: At the conclusion of our time together, you should be able to:.
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Periodic Table Trends
Trends of the Periodic Table:At the conclusion of our time together, you should be able to: Give a trend across and down the Periodic Table for metallic characteristics, reactivity, atomic radius and ion radius, electron affinity, ionization energy, electronegativity, density, melting point and boiling point Pick the element with the higher trend above from a list of several elements
Atomic Radius ½ the distance between the nuclei of two identical atoms that are bonded together. • Electron – electron repulsion Makes radius larger • Very weak interactions
Atomic Radius con‘t 2. Proton – electron attraction = Makes radius smaller Very Strong interactions
Proton electron attraction is a million times stronger than electron electron repulsion
Atomic Radius con’t Down a group/family 3. Energy level, n, increases from top to bottom Radius gets larger by adding large amounts of electrons Think Bohr model (adding rings)
Electron Affinity The energy change that occurs when a neutral atom acquires an electron.
Ionization Energy The energy required to remove one electron from a neutral atom. The closer to the nucleus, the harder to pull the electron. The farther away, more interference from other electrons, therefore, the easier it is to pull the electron.
Electronegativity The ability of an atom to attract electrons. The most electronegative element is F – Fluorine It is assigned the number 4 and all other values are based on that value.
Ionic Radius • Cations lose electrons, therefore they tend to be Positive Ions - Metals • Anions gain electrons, therefore they tend to be Negative Ions - Nonmetals
Ionic Radius Trends More electron – electron repulsion = larger radius Less electron – electron Repulsion = smaller radius
Anion radius is larger compared to the atom Cation radius is smaller compared to the atom
Metallic Character Lowionization energy Lowelectronegativities High luster – shiny Good conductor or electricity and heat Malleable and ductile Most metallic element = Francium
Metallic Characteristic Trends Conductivity Shininess Malleability Ductility
Non Metallic Character Highionization energy Highelectronegativities Little or no metallic luster Poor electrical and thermal conductors Fewer solids Most nonmetallic element = Fluorine
Metalloid Character Characteristics of both metals and nonmetals Electronegativitiesbetween those of metals and nonmetals Ionization energies between those of metals and nonmetals. Boiling pts, Melting pts and Densities vary widely
Silicone High luster Brittle 3. Good conductor
Density Mass of a Material / Volume of that Material
Boiling Point Temperature at which a system moves from the liquid state to the gaseous state. The external pressure pushing into the liquid is equal to the internal pressure pushing out of the liquid.
Melting Point The temperature at which a solid becomes a liquid. The external pressure pushing into the solid is equal to the internal pressure pushing out of the solid.
Trends of the Periodic Table:Let’s see if you can: Give a trend across and down the Periodic Table for metallic characteristics, reactivity, atomic radius and ion radius, electron affinity, ionization energy, electronegativity, density, melting point and boiling point Pick the element with the higher trend above from a list of several elements