Sunday, September 13, 2009

9/11/2009

Oxygen atom on periodic table

8

O

15.9994

[He] 2s^2 2p^2

Isotopes

Isotopes are atoms of the same element that have different masses.

The Isotope of a particular element all have the same number of protons and electrons but different numbers of neutrons.

Most of the elements consist of mixtures of Isotopes .

Mass Number

Mass number is the total number of protons and neutrons that make up the nucleus of an isotope.

-The Atomic mass is a decimal

Designating Isotopes

Hyphen Notation: The mass number is written with a hyphen after the name of the element.

- Uranium – 235

Nuclear symbol: The superscript indicates the mass number and the subscript indicates the atomic number

- Mass Number Þ235 U

- Atomic NumberÞ92

The number of neutrons is found by subtracting the atomic number from the mass number.

- Mass number – Atomic number= Number of Neutrons

- 235 – 92 = 143 for U

Nuclide is a general term for a specific Isotope of and element.

8 comments:

  1. http://www.ndt-ed.org/EducationResources/HighSchool/Radiography/atomicmassnumber.htm
    this website explains mass number and atomic number

    ReplyDelete
  2. http://www.chemicool.com/

    link to periodic table with much iformation on every element

    ReplyDelete
  3. http://www.colorado.edu/physics/2000/isotopes/index.html

    this websites eplians isotopes and helped me understand them

    ReplyDelete
  4. http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nucnot.html

    This website explains isotopes and nuclear notation.

    ReplyDelete
  5. Helps explain Isotopes with helpful pictures

    http://www.colorado.edu/physics/2000/isotopes/index.html

    ReplyDelete
  6. http://www.nclark.net/PeriodicTable

    is a teachers website on the periodic table comeplete with labs, worksheets, and even more helpful links
    ;)

    ReplyDelete
  7. http://ie.lbl.gov/education/isotopes.htm

    This periodic table lists all (known) isotopes of all elements.

    ReplyDelete
  8. http://www.economicexpert.com/a/Atomic:number.htm

    Here is a site about atomic number

    ReplyDelete