1 / 10

Atomic Theory

Atomic Theory. Early Theory. Democritus (400 BC) thought the world was made of tiny particles Aristotle believed that all matter was made up of 4 elements: Fire Earth Water Air. John Dalton. Believed that… All matter is composed of extremely small, indivisible particles called atoms

dasha
Download Presentation

Atomic Theory

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. Atomic Theory

  2. Early Theory • Democritus (400 BC) thought the world was made of tiny particles • Aristotle believed that all matter was made up of 4 elements: • Fire • Earth • Water • Air

  3. John Dalton Believed that… • All matter is composed of extremely small, indivisible particles called atoms • All atoms of a given element are identical • Atoms cannot be created or destroyed • Atoms combine to form compounds

  4. J.J Thompson • The discovery of electrons and protons led to Thompsons plum pudding model of the atom. • “Chocolate chip cookie model” • Positive background speckled with negative particles

  5. Terms: • Nucleus: dense middle of the atom • Electrons: negatively charged particles around the nucleus, “cloud” formation. • Protons: positively charged particles found in the nucleus • Neutrons: no charge, or neutral particles also found in the nucleus

  6. Ernest Rutherford • Found most of the mass in the middle of the atom • Nucleus= protons and neutrons • Electrons form a cloud around the nucleus

  7. Neils Bohr • Believed electrons to be found in orbital paths around the nucleus. • Mapped out where they are most likely to be found

  8. Atomic number = number of protons • Atomic mass = p+ + n° • p+ = e-

  9. 184 W 74 19 F 9 80 Br 35 Practice Find the number of protons number of neutrons number of electrons atomic number mass number

  10. Isotopes: Different forms of the same element based on the number of neutrons in the nucleus

More Related