1. The Periodic Table Introduction to the Periodic Table
Representative Elements
Transition Elements

2. Development of the Periodic Table
In 1830 there were 55 elements isolated and named
Dmitri Mendeleev’s (1869) developed a Table of Elements by ordering them in increasing atomic mass
Elements with similar properties fell into groups
Mendeleev left 3 spaces for elements yet to be discovered and spurred interest in finding those elements (he also predicted their properties
(15 years later all were identified)

3. Moseley’s Contribution
Henry Moseley improved periodic table by placing them in increasing atomic number
This made it possible to see exactly how many elements yet to be discovered

4. Today’s Periodic Table
Ordered by increasing atomic number (protons)
Organized in rows call periods (1-7 rows)
Properties change gradually from 1 row to next
Columns on the periodic table are called groups or families (18 groups)
Groups contain elements with similar physical and chemical properties
Representative elements (8 groups) are from groups 1,2,13-18)
Include elements that are metals, nonmetals, metalloids

5. Today’s Periodic Table
Transition elements: elements from group
All are metals
Inner transition elements are below main table and include lanthanide and actinide series
(named by series that follows lanthanum and actinium (most are radioactive)

8. Metals Are solid (with exception of Mercury Hg)
Have high melting point
Has metallic luster, good conductor of heat and electricity
Is malleable (can hammer it)
Is ductile (can be stretched)

9. Nonmetals and metalloids
Nonmetals are usually
Gases or brittle solids at room temperature
Poor conductors of heat and electricity
17 nonmetals, some are essential for life (O, C,S, N, P, and I)
Metalloids are usually:
In between metals and nonmetals that share properties of metals and nonmetals

10. Element Key
Shows name of element, symbol, atomic number, atomic mass and the state of matter (gas, liquid or solid)

11. Symbols for the Element
One or two letter symbols where the first letter is capitilized, second letter is small letter ie Ca, Pb, Na, Si
Some names come from first letter of element, others greek or latin names, some for countries discovered

12. Representative elements
Groups 1 and 2
Both groups are active metals (except H) because they easily combine with others substances
H shares properties with these groups

13. Alkali metals
Group 1
Silvery solids with low density and low melting points
As move down the column they become more reactive
Include Li,Na,K,Rb,Cs, Fr

14. Alkaline Earth Metals Group 2
Denser, harder and higher melting point than group1 (alkali)
Are reactive, but not as much as alkali metals

15. Groups 13-18 Group 13 Boron Family Group 14 Carbon Family
all are metals except B which is a metalloid
Cookware is made from B, Al for cans,Ga used in computer chips
Group 14 Carbon Family
C is nonmetalic, Si and Ge are metalloids, Tn and Pb are metals
Semi conductors in computers are made from Si because they conduct some electrical current but is buffered to help maintain certain levels of conductivity

16. Groups 13-18 Group 15: Nitrogen groups
N,P,As,Sb,Bi (nonmetal,metalloid, and metals)
Nitrogen composed of 78% of atmosphere yet it can’t be utilized by organisms until it is change to nitrates
Nitrogen fixing bacteria on roots of organisms can fix nitrogen into nitrates

17. Groups 13-18 Group 16 Oxygen Family O and S are essential for life
Te and Po are both metalloids
20% earths atmosphere is made of O
Needed for respiration for energy production of animals
O is needed for combustion, ozone layer protects us from ultraviolet radiation
S is solid, yellow nonmetal, used in sulfuric acid, production of fertilizers, rubber etc
Se is important as trace minerals, conducts electricity

18. Groups 13-18 Group 17 Halogen family
All are nonmetals except At radioactive metalloid
Halogen means salt-former like NaCl
All halogens make salt
As move down the group they become less active

19. Groups 13-18 Group18 The Noble Gases
All are gases, do not react with other elements
Uses include the Neon lights in advertisments
Electricity passes through tubes containing noble gases that when mixed with noble gases produces different colored lights
Bottom of group is radioactive Ra

20. Transition Elements Metals in the Middle: groups 3-12
Iron Triad (similar properties)
Iron Fe, cobalt Co, and nickel Ni
Fe used with other metals and C to form alloys like steel
Uses of Transition Elements
Higher melting points, used in filaments of lightbulbs: tungsten W has highest melting point (3410℃)
Mercury Hg, lowest melting point -39℃
Platinium group Ru,Rh, Pa, Os, Ir, Pl similar properties
Catalysts are substanes that can make something happen faster but doesn’t change themselves (platinium group)

21. Inner Transition Element
Lanthanides series: rare earths because not found commonly on earth
Soft metals, hard to tell apart in same ores, Ce makes up 50%of an alloy called misch used in flints lighters
Actinides series: all are radioactive Th, Pa and U are only ones found in nature
Rest are synthetic elements (man made)

22. Inner Transition Element
Dentistry and Dental Material
Amalgam (mixture of silver, copper, tin, and mercury) is the silver filling
Nickel and titanium alloys are used in wires on braces