Periodic trends
Upcoming SlideShare
Loading in...5
×
 

Like this? Share it with your network

Share

Periodic trends

on

  • 10,186 views

This is a short presentation on the trends found in the periodic table.

This is a short presentation on the trends found in the periodic table.

Statistics

Views

Total Views
10,186
Views on SlideShare
4,779
Embed Views
5,407

Actions

Likes
2
Downloads
95
Comments
0

9 Embeds 5,407

http://my-ecoach.com 4134
http://www.my-ecoach.com 1230
https://my-ecoach.com 36
http://www.google.com 2
http://blackboard.pusd.org 1
http://webcache.googleusercontent.com 1
https://www.masterfun.net 1
http://www.google.co.uk 1
http://barbara.bray.my-ecoach.com 1
More...

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Periodic trends Presentation Transcript

  • 1. Objectives
    • Define atomic and ionic radii, ionization energy, electron affinity, and electronegativity.
    • Compare the periodic trends of atomic radii, ionization energy, and electronegativity, and state the reasons for these variations.
    • Define valence electrons, and state how many are present in atoms of each main-group element.
    Section 2 Periodic Trends
  • 2. Atomic Radii
    • The boundaries of an atom are fuzzy, and an atom’s radius can vary under different conditions.
    • To compare different atomic radii, they must be measured under specified conditions.
    • Atomic radius - one-half the distance between the nuclei of identical atoms that are bonded together.
    Section 2 Periodic Trends
  • 3. Atomic Radii Section 2 Periodic Trends
  • 4. Atomic Radii
    • Atoms tend to be smaller as you go from left to right on the periodic table.
    • This is due to increasing positive charge in the nucleus, pulling the electrons closer to the center.
    • Atoms tend to be larger down a group.
    • This trend is due to the increasing size of the electron cloud as electrons fill up larger energy levels.
    Section 2 Periodic Trends
  • 5. Atomic Radii Section 2 Periodic Trends
  • 6. Ion definition Section 2 Periodic Trends
    • Watch the video on entitled “Ion definition” found in this section of the course
  • 7. Ionic Radii trends Section 2 Periodic Trends
  • 8. Ionic Radii trends Section 2 Periodic Trends
    • Positive ions tend to be smaller than neutral atoms.
    • The larger the positive charge, the smaller the ion.
    • Again, this is due to increasing positive charge in the nucleus, pulling the electrons closer to the center.
  • 9. Ionic Radii trends Section 2 Periodic Trends
    • Negative ions tend to be larger than neutral atoms.
    • The more negative the charge, the larger the ion.
    • This is due to the repelling forces between electrons, causing them to occupy a larger space around the atom
  • 10. Ionization Energy Section 2 Periodic Trends
    • The process to form an ion is called ionization.
    • The energy required to remove one electron from a neutral atom is called ionization energy .
    • Sometimes refered to as IE 1 or first ionization energy .
  • 11. Ionization Energy Section 2 Periodic Trends
    • Ionization energies increase across a period.
    • Caused by increasing effect nuclear charge
    • Higher positive charge more strongly attracts electrons in the same energy level
  • 12. Ionization Energy Section 2 Periodic Trends
    • Ionization energies decrease down a group.
    • Electrons removed from larger atoms are at higher energy levels, and are farther away from the nucleus.
    • Electrons are removed more easily due to their distance from the nucleus.
  • 13. Ionization Energy Section 2 Periodic Trends
  • 14. Ionization Energy Section 2 Periodic Trends
    • Watch the “Ionization” in this lesson when you get to this slide before continuing.
  • 15. Electron affinity Section 2 Periodic Trends
    • The energy change that occurs when an electron is acquired by a neutral atom is called electron affinity.
    • Electron affinity generally increases across periods.
    • Electron affinity generally decreases down groups.
    • All these can be explained by effective nuclear charge and by the distance of an electron from the nucleus.
  • 16. Electron Affinity Section 2 Periodic Trends
    • Watch the video on “Electron Affinity” that is included in this lesson.
  • 17. Valence electrons Section 2 Periodic Trends
    • Compounds form because electrons are lost, gained, or shared between atoms.
    • Electrons involved in this behavior are called valence electrons.
    • Valence electrons are the outermost energy level electrons in an atom.
    • Atoms tend to want to have a full set of 8 valence electrons to be stable.
  • 18. Valence electrons Section 2 Periodic Trends
    • Watch the video on “Valence electrons” included in this lesson.
  • 19. Electronegativity Section 2 Periodic Trends
    • Valence electrons hold atoms together in compounds.
    • In many compounds, the negative charge of the electrons is concentrated closer to one atom than another.
  • 20. Electronegativity Section 2 Periodic Trends
    • Electronegativity is the ability of an atom in a compound to attract electrons from another atom in the compound.
    • Electronegativity generally increases across rows, and decreases down a group
  • 21. Electronegativity Section 2 Periodic Trends
    • Watch the video on “Electronegativity” found in this lesson.
  • 22. Summary of periodic trends Section 2 Periodic Trends