1 / 15

Sub-atomic Particles

Sub-atomic Particles. Going inside the atom!. Nucleus. The “center” of the atom Remember…total charge of an atom is neutral But…the nucleus is a “net” positive charge Protons & Neutrons Protons = positive Neutrons = neutral (help in holding nucleus together). Nucleus Model.

chaim-olson
Download Presentation

Sub-atomic Particles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sub-atomic Particles Going inside the atom!

  2. Nucleus • The “center” of the atom • Remember…total charge of an atom is neutral • But…the nucleus is a “net” positive charge • Protons & Neutrons • Protons = positive • Neutrons = neutral (help in holding nucleus together)

  3. Nucleus Model

  4. Rutherford’s Model

  5. Outside the Nucleus • Electrons • Negative charge • Balance the total (net) charge of the atom • # electrons = # protons • Located around the nucleus • Bohr  Electron Cloud Model

  6. Evolution of the Atom

  7. Values associated with Atoms • Atomic Number = # protons • Atomic Mass = # protons + # neutrons • # neutrons = Atomic Mass - # protons • Neutrons help bind nucleus…act as a glue • Neutron # can vary for an element • Isotopes – same element, but different neutron value • Don’t forget…Everything is in balance!!! • # electrons = # protons

  8. Organizing the Elements • Mendeleev’s Card Game • Noticed a pattern while playing cards • Increasing Numbers…Different suits

  9. Mendeleev’s Idea • Some elements were known…but not many • New elements were being discovered • Each element had its own atomic weight (mass) • Arrange elements based on their weight!!!

  10. Gaps in the Idea • Some elements were not yet discovered • Validity to his concept • By leaving gaps, new elements should fit in • They did!!! • He predicted the discovery of an element like aluminum “eka-aluminum” • It was discovered shortly there-after

  11. Organization of the Modern Table • Periodic means repeating • Periods are repeating sets • Periods go across the table (rows) • Change from Atomic Mass to Atomic Number • Increasing value in # protons

  12. The Info in the Table • Atomic # - always the same for an element • Element Symbol (abbreviation) • Element Name ( sometimes) • Atomic Mass – average value based on common isotopes • Based on atomic mass unit (amu) • 1/12 of the carbon 12 atom

  13. The Periodic Table

  14. Periodic Patterns • Patterns of the elements repeat • Going down the table (columns) shows repeating patterns • Elements in a “Group” share characteristics • Chemical Properties are shared within a group The Periodic Law!!!

  15. Classes of Elements • Metals • Majority of elements • Good conductors • Solids at room temp (except for Mercury) • “Transition Metals” bridge the table • Nonmetals • Opposite of metals • liquid, gas, poor conductor • Metalloids • Between metals and nonmetals • Change conductivity based on temperature • Metals are the left…becoming Nonmetals on the right • Most reactive metals on left • Most reactive nonmetals on right

More Related