Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Atomic Structure What’s in an atom? History of the Atom 460 BC Democritus develops the idea of atoms he pounded up materials in his pestle and mortar until he had reduced them to smaller and smaller particles which he called ATOMA (Greek for indivisible) History of the Atom 1808 John Dalton suggested that all matter was made up of tiny spheres that were able to bounce around with perfect elasticity and called them ATOMS History of the Atom 1898 Joseph John Thompson found that atoms could sometimes eject a far smaller negative particle which he called an ELECTRON Structure of the Atom • Nucleus: The “core” of the atom • The nucleus of the Atom contains 2 types of particles. • Proton: The particle in the nucleus having a positive charge. • Neutron: The particle in the nucleus that has a neutral charge. Using the Periodic Table Look at the tile on the periodic table, Carbon, for example: Name of Element Atomic Number Symbol of Element Atomic Mass Terms Atomic Number: How many protons are in an element. For example, ANY atom that has 6 protons is always called Carbon. Atomic Mass: How many neutrons AND protons are in an element’s nucleus. This number is an average of the different kinds of an element. Using the Periodic Table Silicon has an Atomic Number of 14. This means it has 14 protons Silicon has an Atomic Mass of about 28, so that means it has 28 protons and neutrons. To find how many neutrons it has, we subtract the Atomic Number from the Atomic Mass. So, 28 – 14 = 14 neutrons. Atomic Structure In an uncharged atom, the number of Electrons is equal to the number of Protons. For Carbon, atomic number 6, atomic mass 12. A “typical” carbon atom will have 6 protons. 12 – 6 = 6 neutrons. And 6 protons means 6 electrons. Group Work Work in your groups and have each member write out and hand in the Element Name, Element Symbol, and number of Protons, Neutrons and Electrons for the following Elements (Look in the back of your book): Neon Helium Bromine Potassium Mercury Tellurium Cobalt Tin Zinc Oxygen