FAMILIES AND PERIODS
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Transcript of FAMILIES AND PERIODS
FAMILIES AND PERIODSThe Periodic Table
Mendeleev
Protons hadn’t been discovered in my time, so I didn’t know about atomic number. I arranged the elements by atomic mass.
I’m Henry Mosley, and changed that in 1913, and reordered the table according to atomic number.
Mendeleev
Periodic tableThe periodic table arranges all the elements in groups according to their properties.
Vertical columns are called GROUPS
There are 18 groups
Groups are also called Families
HH HHee
LiLi BBee BB CC NN OO FF NN
eeNNaa
MMgg AlAl SiSi PP SS ClCl ArAr
KK CCaa FeFe NiNi CC
uu ZnZn BrBr KrKr
AAgg II XeXe
PtPt AAuu
HHgg
The Periodic TableElements in the same group
have the same number of electrons in the outer shell. These are called valence
electrons.
All group 1 metals have 1 electron in their outer shell
These elements have 8 electrons in their outer shell
These elements have 3 electrons in their outer shells
HH HHee
LiLi BBee BB CC NN OO FF NN
eeNNaa
MMgg AlAl SiSi PP SS ClCl ArAr
KK CCaa FeFe NiNi CC
uu ZnZn BrBr KrKr
AAgg II XeXe
PtPt AAuu
HHgg
The Periodic TableSince they have the same number
of valence electrons, all of the elements in the same group have similar PROPERTIES. This is how I thought of the periodic table in the
first place.
Consider the group 1 metals. They all:1) Are soft2) Can be easily cut with a knife3) React with water
Mendeleev
Periodic tableThe periodic table also arranges the elements in rows, or periods according to the number of energy levels.
Horizontal rows are called PERIODS
There are 7 periods
Mendeleev
The first element in a period is usually an active solid, and the last element in a period is always an inactive gas.
Elements in a period are NOT alike in
properties.
HH HHee
LiLi BBee BB CC NN OO FF NN
eeNNaa
MMgg AlAl SiSi PP SS ClCl ArAr
KK CCaa FeFe NiNi CC
uu ZnZn BrBr KrKr
AAgg II XeXe
PtPt AAuu
HHgg
The Periodic TableMost of the elements are
metals:These elements are metals
This line divides metals from non-metals
These elements are non-metals
Physical properties of metals Atoms packed together closely. Layers of atoms can slide over one
another Malleable (bendable) Ductile (stretchable) Conduct heat and electricity Usually have high melting and boiling
points Exceptions: Mercury and Group I metals.
Physical properties of metals They have metallic lustre (they’re
shiny) They are sonorous (make a ringing
sound when hit) All except mercury are solids at
room temperature Only a few metals are magnetic. Magnetism is not a property of most
metals!
•very reactive metals that do not occur freely in nature •softer than most other metals•can explode if they are exposed to water
ALKALI ALKALI METALSMETALS
Group 1: Alkali Metals
http://www.youtube.com/watch?v=uixxJtJPVXk
Li Na K Rb Cs
•very reactive•not found free in nature
ALKLINE ALKLINE EARTH EARTH
METALSMETALS
•ductile and malleable, and conduct electricity and heat •iron, cobalt, and nickel, are the only elements known to produce a magnetic field.
TRANSITION TRANSITION METALSMETALS
OTHER OTHER METALSMETALS
•are ductile and malleable •are solid, have a relatively high density, and are opaque
NON-NON-METALSMETALS
•not able to conduct electricity or heat very well•very brittle, cannot be rolled into wires or pounded into sheets•usually exist as gases, sometimes as solids (such as carbon), and bromine is a liquid •have no metallic luster, and do not reflect light.
HALOGENHALOGENSS
•"halogen" means "salt-former" and compounds containing halogens are called "salts" •exist in three states of matter:
•Solid - Iodine, Astatine •Liquid - Bromine •Gas - Fluorine, Chlorine
HALOGENHALOGENSS
•The halogens are non- metals•They all have seven electrons in their outer shell this makes them very reactive since they only have to gain one more electron to fill their outer shell.•Unlike Group One the elements get less reactive as you go down the group
Group 17: The Halogens http://www.youtube.com/watch?v=u2og
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F Cl Br I
NOBLE NOBLE GASESGASES
•do not form compounds easily•have filled outer energy levels
Group 18: The Noble Gases http://www.youtube.com/watch?v=QLrof
yj6a2s
He Ne Ar Kr Xe
MetalloidsMetalloids
•Metalloids are a group of elements that exhibitProperties of both metals and non-metals.•Stair-step pattern divides metals(left) and non-metals(right)
RARE RARE EARTH EARTH
ELEMENTSELEMENTS
•many are man-made
RARE RARE EARTH EARTH
ELEMENTSELEMENTS
•Broken into two groups. •Lanthanides•Actanides
RARE RARE EARTH EARTH
ELEMENTSELEMENTS
•Lanthanides- Top row. • non-radioactive metals• used in making glass
RARE RARE EARTH EARTH
ELEMENTSELEMENTS
•Actanides – Bottom row• Radioactive• Expensive - $$$• Found only in trace amounts
Your Task Today! Create a Key on your periodic table to
help you understand the different groups.
Create a colored box and provide a title for that group.
Write a brief description of the group Ie: a Dark blue box = Alkali Metals – Very
reactive, one valence electron, become more reactive as we go down the family, soft metals, react with water.