Elements in our universe

By: Jonathan Choong 1A1 (10):DElements in our universeContentsDefinition of elementsAtomic mass ,atomic number and isotopesElement namesAtomic bomb?Use of elements/compoundsDiscovery of elementsHow elements are formedAbundance of elementsProperties of elementsBibliography

Definition of an elementAtomic nucleus contains neutrons and protons also known as nucleons.Achemical elementis a purechemical substanceconsisting of onetypeofatomdistinguished by itsatomic number, which is the number ofprotonsin itsnucleus.

Atomic number, atomic mass and isotopesThe atomic number indicates the number of protons within the nucleus of an atomAtomic mass is the mass of an atom measured in atomic mass units, when the atom is at rest at its lowest energy level.Isotopes are elements of different forms. This is caused by the varying number of neutrons in each atom. Isotopes may have the same atomic number but different atomic mass.

Atomic bomb?Weapon getting its explosive force from the release of atomic energy through the fission (splitting) of heavy nuclei.Nuclear energy is the energy stored in thenucleusof an atom and released through fission, fusion, or radioactivity. In these processes a small amount of mass is converted toenergy.HalogensCompounds that contain halogens are known as salts group 17.For example, sodium chloride is made up of chlorine which is a halogen.How elements are formedNucleosynthesisis the process of creating new atomic nuclei from pre-existingnucleons(protons and neutrons).Stellar nucleosynthesis As the star undergoes stellar evolution , it generates elements fromcarbontoironbynuclear fusionprocesses.nuclear fusionis the process by which multiple atomic nuclei join together to form a single heavier nucleus.Abundance of elementsHydrogen is the most abundant element in the universe, followed by oxygen.

Properties of elementsElements on the periodic table are classified into alkali metal, alkaline earth, basic metal, halogen, noble gas, non-metal, rare earth, semi-metal, transitional earth.Periodic table is organised according to similar properties, groups also have similar properties and one can predict the properties of an element by observing where it is place on the periodic table.bibliographyhttp://en.wikipedia.org/wiki/Nucleosynthesis#Processeshttp://www.encyclopedia.com/topic/atomic_bomb.aspxhttp://www.newworldencyclopedia.org/entry/Isotopehttp://en.wikipedia.org/wiki/Nuclear_fusionhttp://www.newworldencyclopedia.org/entry/Atomic_masshttp://www.chemicalelements.com/groups/halogens.htmlhttp://www.ask.com/wiki/Abundance_of_the_chemical_elements