The periodic table
Download
1 / 23

The Periodic Table - PowerPoint PPT Presentation


  • 53 Views
  • Uploaded on

The Periodic Table. Chapter 6. A quest for accurate reproduction. J.W. Dobereiner – published his triad classification system (ex. Cl,Br,I similar chemical properties) 1860 Scientists agreed upon a method to measure mass Are masses related to elemental properties? John Newlands

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' The Periodic Table' - hanzila


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

A quest for accurate reproduction
A quest for accurate reproduction

  • J.W. Dobereiner – published his triad classification system (ex. Cl,Br,I similar chemical properties)

  • 1860

    • Scientists agreed upon a method to measure mass

    • Are masses related to elemental properties?

  • John Newlands

    • Noticed every 8th element had similar properties

    • Law of octaves



Dimitri mendeleev 1869
Dimitri Mendeleev - 1869

  • Organized the periodic table based on increasing atomic mass

  • Predicted the properties of unknown elements

    • Sc, Ge, Ga

P. 181 - Q 24, 25


Henry moseley
Henry Moseley

  • Arranged elements based on the number of protons

  • Determined periodic law

    • Groups have similar properties

    • Properties change as you move across a period

    • Pattern repeats one period to the next

P.181 - Q – 26, 27


Terminology
Terminology

  • Groups (Families) – (IUPAC labels 1-18)

  • Periods

  • Representative elements(1A – 8A)

    • Wide array of chemical and physical properties

    • Group number indicates number of valance electrons

  • Transition elements

  • Metalloids

  • Metal

  • Non metals

P. 181 - Q - 31


Metals
Metals

  • Shiny, smooth

  • Good electrical and heat conductors

  • Malleable, ductile

  • Solid at room temp

  • Reactive Alkali’s and Alkaline’s (s block)


Transition metals
Transition Metals

  • D and F (Inner transitional metals) block

  • Lanthanides and Actinides

P. 181 - Q 33, 34, 35 – P. 182 – 48, 49, 53, 54


Non metals
Non-Metals

  • Most of p block

  • gases or brittle solids (Br)

  • Little luster

  • Poor conductors

  • Halogens very reactive

  • Noble Gases (Inert Gases) - extremely unreactive due to filled s and p sublevels

P. 181 – 28, 32


Metalloids
Metalloids

  • Share properties of metals and non-metals

  • Heavy step line – B, Si, Ge, As, Sb, Te, Po, At

  • Found in p block

P. 181 - 29


Atomic radius
Atomic Radius

Metals - Half the distance between adjacent nuclei in a crystal of an element.

Non Metals - Half the distance between bonded atoms of the same element (diatomic molecule).


Atomic radius family trends
Atomic Radius – Family Trends

Atomic charge and occupied energy levels increase.

Occupied orbitals shield electrons in the outer most energy level from the pull of the nucleus.

Increases


Atomic Radius – Period Trends

decreases

  • Increasing positive charge pulls the valence electrons closer to the nucleus.

  • Shielding does not influence this trend because the effect is constant.

P. 181 - Q - 36 - P. 182 - Q - 50


Ions atoms gain or lose electrons to have a complete set of valence electrons octet rule
Ions – Atoms gain or lose electrons to have a complete set of valence electrons (Octet Rule)

Empty outer orbital or energy level makes it smaller. Electrostatic repulsion decreases.

11 p  10 e

Na

Na+1

11 protons

11 electrons

11 protons

10 electrons


Increased electrostatic repulsion
Increased electrostatic repulsion of valence electrons (Octet Rule)

Cl

17 Protons

17 Electrons

Cl1-

17 Protons

18 Electrons


Ionic radius family trends
Ionic Radius – Family Trends of valence electrons (Octet Rule)

  • Principle energy levels increase in size.


Ionic radius period trends
Ionic Radius – Period Trends of valence electrons (Octet Rule)

3

protons

2 electrons

4

protons

2 electrons

5

protons

2 electrons

6

protons

2 electrons

7

protons

10 electrons

8

protons

10 electrons

9

protons

10 electrons

Electron repulsion decrease

Electron repulsion decrease

P. 181 - Q - 41, 42 - P. 182 - Q -52 - P. 183 - Q - 64, 65


Ionization energy energy needed for an atom to lose an electron
Ionization Energy – energy needed for an atom to lose an electron

Be  Be+  Be2+  Be3+

kilojoules/mol or kj/mol

1s2 1s2 1s2 1s1

2s2 2s1


1 electronst ionization energies increase as you move across a period due to the increased attraction of the nuclear charge.

The stability of the filled sub level affects the ionization energy.

P. 181 – Q - 37, 38, 40 – P. 182 – Q – 55, 58 – P. 183 – Q – 67B


Ionization energy family trends
Ionization Energy – Family Trends electron

Decreases as you move down a family. The further the electron from the nucleus the easier it is to remove.

P. 181 - Q - 39


Electronegativity a measure of an atom s ability to attract an electron
Electronegativity – a measure of an atom’s ability to attract an electron

P. 181 - Q - 43, 44, 45


ad