chemistry

Brief Discussion of Periodic Table Elements 1. Introduction  We know that 118 elements have been discovered so for. A table in which similar elements are placed in the same group is called a periodic table. A periodic table is the most significant achievement in the field of chemistry. It serves the students to know the properties of elements in a systematic way. It is the basic framework to study the periodic variations in the physical and chemical behavior of elements or their compounds. The modern periodic table is used to organize all the known elements. Elements are arranged in the table by increasing the atomic number. In the modern periodic table, each element is represented by its chemical symbol (Levi and Rosenthal, 1984; Kitaev, 2009). Columns of the periodic table are called groups. Elements in the same group have similar properties. For chemistry students and teachers: The tabular chart on the right is arranged by an Atomic number. The first chemical element is Hydrogen...

A collection of well defined distinguished object is called set. Example A=[1,2,3,4,5,6,7....]

INTRODUCTION In recent years, metal nanoparticles and thin films supported on oxides have become fundamental components of many devices as their small dimensions present structures with new chemical and physical properties, often enhancing the reactivity of these surfaces relative to their bulk counterparts. Numerous theoretical and experimental studies show that the metal particle size and shape as well as direct adsorbate interactions with the oxide support can each play a key role in enhancing the reactivity of these surfaces.  Further investigations imply that the support material mayalso influence the metal’s intrinsic reactivity at these surfaces.  However, these studies were not able to isolate this effect from those of particle size, shape, and direct adsorbate-support interactions. It was not until recently that Chen and Goodman probed the influence of the oxide support material on the intrinsic properties at the metal surface. By covering a titania support with one o...