Periodicity


 * Periodic Trends**

Compare (and account for) the trends across Period 2 and Period 3 with respective to the following properties: 1. Melting point 2. Metallic character – to also look into (a) type of ions formed; (b) type of oxides formed 3. Atomic radius 4. Ionization Energy 5. Electronegativity Reference site: @http://www.rsc.org/education/teachers/learnnet/ptdata/table/index.htm @http://www.chemicool.com/


 * 1. Melting point**
 * [[file:311_ManLin_PTtrends.pages]](editted after Ms Jazilah's comments)**

Comments: - Focus on structure of elements, instead of the bonding (e.g. Giant Ionic lattice, Giant metallic lattice) - Van de waals forces (not bonding, but attractive forces) - Misunderstanding about macromolecules: Do not have intermolecular forces, one giant covalent molecule - Generalizations/Trends: The melting point changes according to the type of structure an element has.


 * 2. Metallic Character**

Comments: -different types of oxides: neutral, amphoteric, acidic, basic -from Period 2 to 8, left to right, the oxides formed are basic, amphoteric and then acidic -Summary: Metallic character decreases from left to right. This is because the number of valence electrons increase from left to right.

Comments: References: Atomic and physical properties of Periodic Table Group 7 (The Halogens) http://webcache.googleusercontent.com/search?q=cache:nRBuaUsmuooJ:www.chemguide.co.uk/inorganic/group7/properties.html+metallic+character+group+7&cd=1&hl=en&ct=clnk&client=safari


 * 3. Atomic radius**

Comments: What are atom orbitals?


 * 4. Ionization energy**

Comments: References: http://www.chemguide.co.uk/atoms/properties/ies.html http://www.rsc.org/education/teachers/learnnet/ptdata/table/index.htm


 * 5. Electronegativity**
 * Comments: **
 * What is principle quantum shell? **
 * Electron affinity VS electronegativity? **
 * Electronegativity must be in context of a chemical bond.... **
 * Element with high electronegativity will have high electron affinity... **