1. Lesson 3 Part The Periodic Table
Chapter 18
Lesson 3 Part
The Periodic Table

2. Dmitri Mendeleev Dmitri Mendeleev (1869, Russian)
Organized elements by increasing atomic mass.
Predicted the existence of undiscovered elements.

3. Henry Mosely Henry Mosely (1913, British)
Organized elements by increasing atomic number. One proton and electron are added to each element as you go across the table.
Fixed problems in Mendeleev’s arrangement.

4. Metallic Character
Metals
Nonmetals
Metalloids

5. Metallic Character
Metals- good conductors of heat and electricity, Malleable (most metals can be hammered into thin sheets)
Nonmetals- gases that are poor conductors of heat and electricity at room temperature, Brittle (breaks easily)
Metalloids- Conduct heat and electricity better than nonmetals but not as well as metals, Can be shiny or dull , Solids

6. Table Sections Representative Elements Transition Metals
Inner Transition Metals

7. Overall Configuration
Table Sections
Overall Configuration
Lanthanides - part of period 6
Actinides - part of period 7

8. Columns & Rows Group (Family) Period 1 18 1 2 13 14 15 16 17 2 3 3 4 59 10 11 12 4 5 6 7

9. Terms
Periodic Law
Properties of elements repeat periodically when the elements are arranged by increasing atomic number.
Moving from left to right in a row of the periodic table, metallic properties decrease.

10. Terms Valence Electrons Atomic Radius First Ionization Energy
e- in the outermost energy level
Atomic Radius
First Ionization Energy
energy required to remove an e- from a neutral atom

11. Atomic Radius Increases to the LEFT and DOWN
Periodic Trends
Atomic Radius
Increases to the LEFT and DOWN

12. First Ionization Energy Increases to the RIGHT and UP
Periodic Trends
First Ionization Energy
Increases to the RIGHT and UP

13. Periodic Trends Group # = # of valence e- (except He)
Families have similar reactivity.
Period # = # of energy levels 1A 2A
3A 4A 5A 6A 7A 8A

14. Orbital Region where there is 90% probability of finding an electron.
Can’t pinpoint the location of an electron
Density of dots represents degree of probability.

15. Orbitals have different shapes

16. Energy Levels Electrons can only exist at certain energy levels.
Low energy levels are close to the nucleus.
Each energy level (n) can hold 2n2 electrons.

17. Bohr Model Diagrams
Simplified energy levels using Bohr’s idea of circular orbits.
Lithium
Atomic #: 3
Mass:
# of p: 3
# of e: 3
# of n: 4
Can replace with: 3p 4n e- e- p n
Maximum e-
Level 1 2e-
Level 2 8e-
Level 3 18e-
Level 4 32e- e-

18. Bohr Model Activity
Choose a number between 1 & 50.
Find your element by the atomic number you picked.
Make a Bohr Model diagram for your element on a piece of cardstock (make sure you put your name on it because you will be turning it in for a grade).
Round off the mass listed on the table and subtract the atomic # to find the # of neutrons.
Abbreviate the # of ‘p’ and ‘n’ in the nucleus.
I have the card stock, yarn, and electrons, protons and neutrons (cereal)