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

MUDBaf4

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.