1. Periodic Table History

2. History of the Periodic Table
Dobereiner
Triads of elements with shared properties
Cannizzaro
method for measuring atomic masses and interpreting the results of measurements
Newlands
arranged elements by atomic masses, properties repeated after every 8 elements → law of octaves

3. History of the Periodic Table
Mendeleev & Meyer
arranged elements according to the increase in atomic mass

4. History of the Periodic Table
Mendeleev
left spaces for undiscovered elements & predicted properties of those elements
credited with discovering periodicity

5. History of the Periodic Table
2 Questions:
Why could most elements be arranged by increasing atomic mass, but a few could not?
What was the reason for chemical periodicity?

6. History of the Periodic Table
Mosely
shooting electrons at various metals to produce X-rays
frequencies of the X-rays were unique to the metals
assigned a whole number to each element → atomic numbers
arrange elements by atomic numbers to get families with similar properties

7. History of the Periodic Table
an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column (group/family)

8. History of the Periodic Table
Periodic Law
the physical and chemical properties of elements are periodic functions of their atomic numbers

9. Periodic Table Information

10. Types of Elements

11. Periodic Table Information
Types of elements:
Metal – lustrous, good conductors, most are solids, malleable, ductile
Nonmetal - poor conductors, no luster, neither malleable nor ductile, most are gases, wide variety of other physical properties
Metalloid - properties of metals & non-metals

12. Parts of the Periodic Table

13. Periodic Table Information
horizontal rows of elements
Group (family)
vertical columns of elements

14. Periodic Table Information
Group (family)
alkali metals – group 1 (except hydrogen)
alkaline earth metals – group 2
transition metals – all of the d-block elements
inner transition metals – all of the f-block elements
metalloids – elements that touch the “staircase”
halogens – group 17
noble gases – group 18 (elements with filled outer shells of electrons)