Chapter 10
This presentation is the property of its rightful owner.
Sponsored Links
1 / 28

Chapter 10 PowerPoint PPT Presentation


  • 61 Views
  • Uploaded on
  • Presentation posted in: General

Chapter 10. Periodic Trends Density Atomic and Ionic Radii. Density. Density. Iridium (Z = 77) has the highest density. Why not Meitnerium (Z = 109?) We can predict that an element is more dense if it is closer to Iridium. Density. Effective Nuclear Charge (Z eff ).

Download Presentation

Chapter 10

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


Chapter 10

Chapter 10

Periodic Trends

Density

Atomic and Ionic Radii


Density

Density


Density1

Density

  • Iridium (Z = 77) has the highest density.

  • Why not Meitnerium (Z = 109?)

  • We can predict that an element is more dense if it is closer to Iridium.


Density2

Density


Effective nuclear charge z eff

Effective Nuclear Charge (Zeff)

  • The effective nuclear charge (Zeff) of an atom is basically how well it is able to hold on to its most loosely held electron.


Atomic radius radii

Atomic radius (radii)

  • Theatomic radius is essentially the size of an atom.

  • The largest atom is Francium (Z = 87).


Chapter 10

Atomic Radius

Xylophone monkey


Rank the atoms from smallest to largest

Rank the atoms from smallest to largest

Na, K, O, N

O < N < Na < K


Atomic radius and effective nuclear charge

Atomic Radius and Effective Nuclear Charge

  • The atomic radius decreases as effective nuclear charge increases.


Effective nuclear charge z eff1

Effective Nuclear Charge (Zeff)

  • The effective nuclear charge of an atom is primarily determined by:

  • The nuclear charge

  • The shielding effect


The nuclear charge z

The Nuclear Charge (Z)

  • Based on the number of protons in the nucleus.

    • Example: Carbon vs. Nitrogen


The nuclear charge z1

The Nuclear Charge (Z)

Carbon

Nitrogen


The nuclear charge z2

The Nuclear Charge (Z)

  • The greater the number of protons in the nucleus the greater the effective nuclear charge.

Nitrogen

Carbon


Chapter 10

Conclusion: Nitrogen is a smaller atom than carbon because nitrogen has 7 protons to pull in its electrons whereas carbon only has 6.

Nitrogen

Carbon


Chapter 10

Nuclear charge explains why atoms get smaller across a period

Atomic Radius

Xylophone monkey


Shielding effect

Shielding Effect.

  • The shielding effect is when electrons between the nucleus and the outermost electrons in an atom shield or lessen the hold of the nucleus on the outermost electrons.


Shielding effect1

Shielding Effect.

He

Ne


Chapter 10

Conclusion: Neon is larger than helium because it has an increased shielding effect from having two energy levels whereas helium only has one energy level.

He

Ne


Chapter 10

Shielding Effect explains why atoms get larger down a group

Atomic Radius

Xylophone monkey


Chemical reactivity

Chemical Reactivity


Chemical reactivity1

Chemical Reactivity


Chemical reactivity2

Chemical Reactivity

  • Metals tend to lose electrons when reacting.

    • Large metal atoms are more reactive.

  • Nonmetals tend to gain electrons when reacting.

    • Small nonmetal atoms are more reactive.


Chemical reactivity3

Chemical Reactivity

  • Metals increase in reactivity left and down.

  • Nonmetals become more reactive up and to the right.

  • Most reactive metal is?

  • Most reactive nonmetal is?

Fr

F


Ionic radius

Ionic Radius

  • Ionic Radius is the size of an ion.


Size change in ion formation

Size Change in Ion Formation


Rules for ionic radius

Rules for Ionic Radius

  • Anions (negative ions) are “always” larger than cations (positive ions).

  • Ionic Radius goes by the same rules as atomic radius (ions get larger as we move down and to the left).

  • However it is necessary to treat anions and cations separately. (Anions are bigger).


Rank the ions from smallest to largest

Rank the ions from smallest to largest

K+, N3-, Na+, O2-

Na+ < K+ < O2- < N3-


Homework

Homework

  • Worksheet: Density, Atomic and Ionic Radii


  • Login