1 / 25

The Atom

The Atom. Ch 3.1. Foundations of Atomic Theory. Law of Conservation of Mass Mass cannot be created or destroyed Law of Definite Proportions Chemical compound always has the same proportions of elements no matter the size Law of Multiple Proportions

tia
Download Presentation

The Atom

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. The Atom Ch 3.1

  2. Foundations of Atomic Theory • Law of Conservation of Mass • Mass cannot be created or destroyed • Law of Definite Proportions • Chemical compound always has the same proportions of elements no matter the size • Law of Multiple Proportions • When elements combine, they do so in the ratio of small whole numbers. The mass of one element combines with a fixed mass of another element 

  3. Dalton’s Atomic Theory • 4. Atoms of different elements combine in simple whole number ratios to form compounds • 5. In chemical reactions atoms combine, separate or rearange • 1. Matter is composed of atoms • 2. Atoms of a given element are identical in mass, size, and properties • 3. Atoms cannot be created or destroyed

  4. Modern Atomic Theory • 2. Atoms of any one element differ in properties from another element • 1. All matter is composed of atoms

  5. The Structure of an Atom Ch 3.2

  6. Subatomic Particles • Electron- • negatively charged, surround the nucleus • Proton- • Positively charged, in nucleus • Neutron- • Neutrally charged, in nucleus

  7. Thompson • Plum Pudding Model • Negative and positive charges spread evenly • Used cathode rays to discover electrons • Found electrons to be negatively charged particles

  8. Rutherford • Used alpha particles to discover the nucleus

  9. Composition of Atomic Nucleus • Positive Charge • Equal in magnitude to the negative chare of an electron(same # of protons and electrons) • Determine atoms identity • Neutral Charge Protons Neutrons

  10. Nuclear Forces • Hold nuclear particles together • Proton- Proton force • Neutron-Neutron Force • Proton-Neutron Force

  11. Counting Atoms Ch 3.3

  12. Atomic Number • The number of protons of each atom in the element • Z • In order on periodic table

  13. Isotopes • Atoms of the same element with different number of neutrons(different mass)

  14. Mass Number • Total number of protons and neutrons

  15. Designating Isotopes • Mass written with a hyphen after the element name • Hydrogen-3 • 1 Proton • 1 Electron • 2 Neutrons • Element mass and atomic # written with the elements symbol Neutrons= Mass-atomic Hyphen Notation Nuclear Symbol

  16. Practice

  17. Relative Atomic Masses • Ex:Oxygen-16 • Mass 16/12 of Carbon-12 • 16 amu • Carbon-12 atom • Standard to compare units of atomic mass • Atomic Mass Unit • 1amu = 1/12 mass of Carbon-12

  18. Average Atomic Mass • Calculating AAM • 1.Multiply atomic mass of each isotope by relative abundance • 2. Add the results • Weighted average of atomic masses of naturally occurring isotopes of an element

  19. Relating Mass to Numbers of Atoms • SI unit for amount of substance • Amount of a substance that contains as many particles as are atoms in 12g of carbon-12 • Number of particles in a mole • 6.022 x 1023 Mole Avogadro's Number

  20. Relating Mass to Numbers of Atoms • Mass of 1mole of a pure substance • g/mol Molar Mass Gram/Mole Conversion

  21. Practice

  22. Practice

  23. Conversions with Avogadro's Number • Avogadro's Number can be used to find • The number of atoms in an element • The amount of an element in moles

  24. Practice

  25. Practice

More Related