The Element Song http:// www.privatehand.com/ flash/elements.html Atoms 0Matter is anything that takes up space and has mass. All matter is made of atoms. 0Atoms are the basic building blocks of matter. They make up everything around us; Your desk, the board, your body, everything is made of atoms! 0Atoms are too small to see without powerful microscopes. Atomic Structure There are two basic components in every atom: Electron Cloud Nucleus Subatomic Particles Three subatomic particles make up every atom: Subatomic Particle Charge Location Proton Positive (+) Nucleus or Core Neutron No Charge (0) Nucleus or Core Electron Negative (-) Electron Cloud
Subatomic Particles Atomic Theory Changes over time Electron Cloud: Electrons orbit the nucleus. Nucleus or Core : Protons and Neutrons are found in the nucleus. Atomic Theory 0Because we cannot see atoms, we use models to teach and learn about atoms. 0The atomic theory has changed over time as new technologies have become available. 0 Remember: Scientific knowledge builds on past research and experimentation. Democritus 460 BC - Greek philosopher proposes the existence of the atom He pounded materials until he made them into smaller and smaller parts He called them atoma which is Greek for indivisible. http://s3.timetoast.com/public/uploads/photos/1765183/democritus.png?1316996277
Democritus His Theory: All atoms: Are small hard particles Are made of a single material formed into different shapes and sizes Are always moving, and they form different materials by joining together Atomic Theory Timeline Scientist Information Model John Dalton All matter is made of atoms. Atoms are too small to see, indivisible and indestructible. All atoms of a given element are identical. John Dalton 1803 - British chemist; elements combine in specific proportions to form compounds Solid Sphere Model or Bowling Ball Model Proposed by John Dalton John Dalton His Theory: All substances are made of atoms that cannot be created, divided, or destroyed. Atoms join with other atoms to make new substances. Atoms of the same element are exactly alike, and atoms of different elements are different in mass and size. http://a5.files.biography.com/image/upload/c_fit,cs_srgb,dpr_1.0,h_1200,q_80,w_1200/mte1oda0otcxntk5otu1ndy5.jpg
Dimitri Mendeleev (Men-da-lay-ev) In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them. Atomic Theory Timeline Scientist Information Model J.J. Thompson Discovered the negative electron, and predicted that there also must be a positive particle to hold the electrons in place. http://a5.files.biography.com/image/upload/c_fit,cs_srgb,dpr_1.0,h_1200,q_80,w_1200/mte5ntu2mze2mzezmdywodc1.jpg J.J. Thomson 1897 - English chemist and physicist; discovered 1 st subatomic particles Plum Pudding Model or Raisin Bun Model Proposed by J.J. Thomson J.J. Thomson His Theory: Atoms contain negatively charged particles called electrons and positively charged matter. Created a model to describe the atom as a sphere filled with positive matter with negative particles mixed in Referred to it as the plum pudding model https://media1.britannica.com/eb-media/85/101085-004-e1192912.jpg
Atomic Theory Timeline Ernest Rutherford Scientist Information Model Ernest Rutherford Discovered the nucleus of an atom and named the positive particles in the nucleus protons. Concluded that electrons are scattered in empty space around the nucleus. 1912 - New Zealand physicist discovered the nucleus Nuclear Model Proposed by Ernest Rutherford https://historyoftheatom.files.wordpress.com/2015/02/ernest-rutherford.jpg Ernest Rutherford His Theory: Small, dense, positively charged particle present in nucleus called a proton Electrons travel around the nucleus, but their exact places cannot be described. Conducted the Gold Foil Experiment https://sakai.ithaca.edu/access/content/user/jkleingardner/principles%20html%20slides/img/ch1/goldfoil.jpg
Atomic Theory Timeline Niels Bohr Scientist Information Model Neils Bohr Concluded that electrons are located in planet-like orbits around the nucleus in certain energy levels. 1913 - Danish physicist; discovered energy levels Bohr Model or Planetary Model Proposed by Niels Bohr http://www.azquotes.com/picture-quotes/quote-a-physicist-is-just-an-atom-s-way-of-looking-at-itself-niels-bohr-3-7-0770.jpg Niels Bohr His Theory: Electrons travel around the nucleus in definite paths and fixed distances. Electrons can jump from one level to a path in another level. Erwin Shrodinger 1924 - Austrian physicist; developed the electron cloud model Electron Cloud Model Proposed by Erwin Schrodinger
Erwin Shrodinger His Theory: The exact path of electrons cannot be predicted. The region referred to as the electron cloud, is an area where electrons can likely be found. Atomic Theory Timeline Scientist Information Model James Chadwick Discovered that neutrons were also located in the nucleus of an atoms and that they contain no charge. Neutrons James Chadwick 1932 - English physicist; discovered neutrons His Theory: Neutrons have no electrical charge. Neutrons have a mass nearly equal to the mass of a proton. Unit of measurement for subatomic particles is the atomic mass unit (amu). Scientist Information Model (Many Scientists!) The Modern Atomic Theory Electrons do not orbit the nucleus in neat planet-like orbits but move at high speeds in an electron cloud around the nucleus. http://chadwicksphysics.weebly.com/uploads/1/7/3/4/17347989/3729228_orig.jpg
Modern Theory of the Atom Atoms are composed of three main subatomic particles: the electron, proton, and neutron. Most of the mass of the atom is concentrated in the nucleus of the atom. Modern Theory of the Atom The protons and neutrons are located within the nucleus, while the electrons exist outside of the nucleus. In stable atoms, the number of protons is equal to the number of electrons. Modern Theory of the Atom Modern Theory of the Atom The type of atom is determined by the number of protons it has. The number of protons in an atom is equal to the atomic number. The sum of the number of protons and neutrons in a particular atom is called the atomic mass. Valence electrons are the outermost electrons.
Atom electron Proton Neutron www.thinkgeek.com/images/products/additional/large/periodic_magents_close.jpg Atom Neutrons Electrons Protons Nucleus Atomic Number = number of protons Atomic Weight = number of protons + number of neutrons Protons = Number of electrons Electron clouds //village.wsfcs.k12.nc.us/lv/hswest/hp.nsf/files/ potassium6/$file/atomic+number.bmp
Hydrogen https://www.youtube.com/watch?v=k5x7eoiq1y0 Halogens 19 Atomic Weight = number of protons + number of neutrons Alkali Metals H Alkaline Earth Metals Transition Metals Noble Gases K Potassium 39.0938 = 19 + neutrons -19-19 20.0938 neutrons 39.0938 There cannot be 0.0928 of a neutron, so this number is rounded to 20 neutrons. Inner Transition Metals by Daniel R. Barnes, init: 11/03/2005 Hydrogen Halogens Hydrogen Halogens Alkali Metals http://www.youtube.com/watch?v=dfqpnhkqlzm Alkaline Earth Metals H Noble Gases He Alkali Metals Alkaline Earth Metals H Noble Gases He Li Be Transition Metals F Ne Li Be Transition Metals F Ne Na Mg Cl Ar Na Mg Cl Ar K Ca Br Kr K Ca Br Kr Rb Cs Sr Ba I At Xe Rn Rb Cs Sr Ba METALS metalloids I At NONMETALS Xe Rn Fr Ra Fr Ra Inner Transition Metals Inner Transition Metals by Daniel R. Barnes, init: 11/03/2005 by Daniel R. Barnes, init: 11/03/2005
Hydrogen Alkali Metals H Li Alkaline Earth Metals Be Transition Metals Metalloids = Semimetals (These words may mean something slightly different from each other.) B Halogens Noble Gases He F Ne Metals Na K Rb Cs Fr Mg Ca Sr Ba Ra Inner Transition Metals Si Ge As Sb Te Cl Br I At Ar Kr Xe Rn Metals are lustrous (shiny), malleable, ductile, and are good conductors of heat and electricity. They are mostly solids at room temp. What is one exception? by Daniel R. Barnes, init: 11/03/2005 Nonmetals Nonmetals are the opposite. They are dull, brittle, nonconductors (insulators). Some are solid, but many are gases, and Bromine is a liquid. Metalloids Metalloids, aka semi-metals are just that. They have characteristics of both metals and nonmetals. They are shiny but brittle. And they are semiconductors. What is our most important semiconductor?
Each row is called a period The elements in each period have the same number of shells Adapted by J. Phillips Written by Liz Rosawww.middleschoolscience.com 2008 All images are from www.chem4kids.com www.chem4kids.com Except for He, it has 2 electrons Each column is called a group Each element in a group has the same number of electrons in their outer orbital, also known as shells. Transition Metals have slightly different rules for shells and valence electrons. This is something you will learn about in High School Chemistry. The electrons in the outer shell are called valence electrons www.chem4kids.com www.chem4kids.com
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Helium is the exception in Group 8. Since it has just one shell, that shell can only fit 2 electrons instead of 8. It is in this group because all the elements have a full outer shell. Have a great day! http://il8.picdn.net/shutterstock/videos/14605225/thumb/2.jpg