Periodic table

download Periodic table

of 19

  • date post

    19-Jan-2015
  • Category

    Technology

  • view

    523
  • download

    1

Embed Size (px)

description

chemistry ppt 2

Transcript of Periodic table

  • 1. PERIODIC TABLE Chemistry Part 2

2. Chemistry

  • A knowledge of chemistry is essential for understanding the structure and function of animals because body functions involve chemical reactions.

3. Matter

  • Matter is anything that occupies space and has mass.

4. Elements

  • Elements Pure substances that cannot be broken down into simpler units.

5. Atoms

  • Atomsare composed of a nucleus and an electron cloud.
  • Nucleus central core of an atom and is made up ofProtons(particle with a positive charge) andNeutron (particle without a charge, its neutral)

6. Atoms

  • Electron cloud electrons around the nucleus
  • Electrons particle with a negative charge

7. Periodic Table

    • Atomic number = number of protons
    • Atomic Mass=
  • Total numbers
  • Of protons plus
  • Neutrons in
  • Nucleus.

8. Isotopes

  • Same atoms; different numbers of neutrons, therefore different atomic mass.
  • Examples:Carbon 12 and Carbon 14
  • Carbon Atomic Number 6, so how many neutrons in Carbon 12?
  • 6
  • Carbon 14?
  • 8

9. Radioisotopes

  • Unstable Isotopes
  • Unstable nuclei, which tend to undergo radioactive decay.
  • Carbon 14 is unstable isotope. (half-life of 5,730 years)
  • Carbon 12 is stable.

10. Electrons

  • Energy levels different locations of electrons around the nucleus
  • First level 2 electrons
  • Second & all other levels 8 electrons

11. Electrons

  • The amount of electrons in the outermost energy level leads to properties of the atom will it react with other atoms?

12. Valence Electrons

  • Number of electrons in outermost shell.
  • If the outer shell is full then NO REACTION!
  • Column 8, valence shell has 8 electrons, it is full, NO REACTION!!
  • Columns 1-7?
  • Fill in info on periodic table.

13. 14. Electron Dot Diagram

  • Illustrates energy levels and the number of electrons in all shells.
  • Can put symbol in center to represent nucleus.
  • Easy way to determine number of valence electrons.

15. 16. Lewis Dot Structure

  • Write symbol for element.
  • Indicate valence electrons by putting dots representing electrons found in OUTER SHELL ONLY. (only show electrons that are available for bonding)
  • Ex:

17. uc 18. Covalent Bonds

  • Atoms SHARE electrons.
  • Use Lewis Dot Structures

19. Ionic Bonds

  • Electrons TRANSFER of electrons.
  • Use Lewis Dot Structure