1. 8th Grade Science-Periodic Table
Properties of the Periodic Table

2. The Periodic Table
Dimitri Mendeleev-arranged all the elements known in order of increasing atomic masses and discovered a pattern
Today’s Periodic Table—elements are arranged by increasing atomic number and by changes in physical and chemical properties

3. Mendeleev-left blank spaces to keep elements in line according to chemical properties
He predicted the existence of two elements not yet discovered

4. Groups
The vertical columns in the periodic table-also called families
Elements in groups have similar properties
Periodic Table—pg. 128 and 129 in textbook

5. *Elements in the same group have the same number of valence electrons
*This means these elements will all bond similarly

6. Periods/Rows Horizontal groups across the periodic table
Each row ends with an element with a full outer valence (8 electrons)
Periods increase by one proton and one electron going L to R

7. Many other properties of elements increase either left to right or right to left across the periodic table as well.
Ex: electronegativity, atomic radii, etc.

8. Metals Metals are on the left-hand side of the periodic table
Most are shiny, ductile, malleable and are good conductors
Ductile—drawn into wire
Malleable-can be hammered into sheets

9. Non-metals Non-metals are on the right side of the periodic table
Most are gases, brittle, are poor conductors, and are solids at room temperature

10. Metalloids Metalloids-run along the middle zig-zag line
Metalloids have some of the properties of both metals and non-metals

11. Metalloids
Are considered semiconductors—can conduct electricity better than nonmetals, but not as well as metals
*Review pg. 135 of book

12. Groups of the Periodic Table
Group 1—Alkali Metals
All have 1 valence electron and are highly reactive
Group 2—Alkaline Earth Metals
All have 2 valence electrons and are reactive, but not quite as reactive as Group 1

13. Groups 3-12
*Called the “Transition Elements” because they are in transition between Groups 1 and 2 and Groups 13-18
*They have no specific number of valence electrons per group

14. Group 13 elements-Boron Group
All have 3 valence electrons
Boron-metalloid-common in some household products-borax, boric acid
Aluminum-most abundant metal in Earth’s crust
(cans, foil, pans, siding)

15. Group 14 elements-Carbon Group
Carbon-silicon, nonmetal, silicon and germanium are metalloids, and tin and lead are metals
Carbon occurs as an element in coal, oil, natural gas, foods
All Group 14 elements have 4 valence electrons

16. Group 15 Elements-Nitrogen Group
All have 5 valence electrons
Tend to share electrons when bonding
Ex: ammonia, fertilizer, nitrates
Phosphorus-water softeners, fertilizers, match heads, china
Antimony and Bismuth-low melting points/mixed w/other metals

17. Group 16 –Oxygen Group All have 6 valence electrons
Exists in air as a diatomic molecule
Ozone-protects us from sun’s radiation
Sulfur-nonmetal, exists in different forms, used as pigment in paint

18. Group 17 Elements-Halogens
All have 7 valence electrons, so very reactive
Form compounds that have many uses-toothpaste, disinfectants, etc.
Form salts when they bond with other elements

19. Group 18 Elements-Noble Gases
Have 8 valence electrons
Satisfy the “octet rule”
Are very stable and do not bond with other atoms in nature
*used for neon signs, lighting, balloons, etc.

20. Lanthanide and Actinide Series
Located at bottom of periodic table
Separated from rest of periodic table to keep other elements in order
Most are man-made elements

21. Synthetic Elements
Scientists break apart elements in order to make new SYNTHETIC elements
Synthetic elements on the periodic table are those with an atomic # greater than 92

22. CHNOPS-Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur
These are the most abundant elements in living organisms

23. Diatomic Elements
These elements exist naturally as diatomic elements (2 atoms bonded together)
Hydrogen Iodine
Nitrogen Chlorine
Fluorine Bromine
Oxygen
Acronym: Have No Fear of Ice Cold Beverages

24. Periodic Table websites: