1. Warm Up 10/2:
1) What does the number two tell you about Helium?
2) How many protons, neutrons and electrons does one neutral atom of helium contain?
3) What are columns on the periodic table called?
4) What are the rows called?
5) What element is represented by the model on the right? How do you know?
6) What is the mass of the atom on the right?

2. What is the name of Group 1A, 7A and 8A?
What type of elements are in groups 3B-2B?

3. Add to “Subatomic Particles” Notes
Mass number: the mass of a particular atom , represented as a whole number, units in “amu”.
Atomic mass: the average mass of all isotopes of an element, units in “amu”.

4. Concept Check (You do not need to write this down.)
What subatomic particles are found in the nucleus of an atom?
What subatomic particle is found outside of the nucleus?

6. Periodic Table of Elements
Trends, Families, Predicting Properties

7. Brief History:

8. Mendeleev’s Table – Published 1869 What’s missing?

9. Ra discovered by Marie Curie - 1898

10. (Add to “Chemical Families” Notes)
How did Mendeleev predict where newly discovered elements would go on the periodic table?
(Add to “Chemical Families” Notes)
Elements in the same group/family have VERY similar chemical properties, and therefore behave (react) VERY similarly

11. Why do elements in the same family behave (react) similarly?

12. Add to “Atomic Structure” Notes
Valence electron: the electrons located in the outermost electron shell of an atom
Core electron: all other electrons in an atom besides the valence electrons
Electron Shell: the levels around the nucleus where electrons can be found. These levels are represented on models by spheres or circles.
Valence shell: the outermost electron shell in an atom.

14. What do you observe in terms of the number of valence electrons and chemical families?

15. What patterns did you notice with electrons and electron shells in main group elements?

16. Periodic Trends: Density
Video Clip:

17. Predicting Properties

18. DO NOW: Read Trends of the Periodic Table Notes Handout
2) Complete Periodic Table Assignment (Directions at the end of Trends of the Periodic Table Handout) – DUE FRIDAY

19. Predicting Properties

20. Predicting Properties