Elements+In+the+Periodic+Table




 * ****Elements** can be found in boxes at the intersection of rows and columns. Each element is described usually by a one letter or two letter acronym or symbol. In addition to an elements name and symbol, each box also describes several other characteristics. At the top left hand corner, one can find the atomic number of the element. This number describes the total mass of the protons neutrons and electrons in a single atom. And on the top right hand corner one can find the atomic weight of the element, which describes the ratio of the average mass of the element to 1/12 the mass of a carbon 12 isotope atom.
 * **__What are the elements that can be naturally found on earth?﻿ __**


 * **__What is the definition of an isotope? And do isotopes change the properties of each element? __**

**__﻿__** Najla Awayda: 1) The first 92 elements apart from Technetium. Neptunium and Plutonium can occur in trace quantinties only where Uranium is found. 2) Any 2 or more forms of a chemical element having the same number of protons in the nucleus, or the same atomic number, but having different number of neutrons,or different atomic weights. Isotopes of a single element possess almost identical properties. 3) It helps in determining the valence state of an element.
 * **__What are the uses for the atomic number of an element? __**

Rinad Bakhti : 1- The elements to be found naturally are the primary 92 elements of the periodic table. 2- An isotope is an element which has an equal number of protons in the nucleus as another element or one with the same atomic number. Isotopes are elements which are similar to one another and have identical properties. 3- Atomic number determines the valence state of an element.