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Periodic Table: FamiliesMarch 3, 2014
The Periodic Table of the Elements: Families!
+ Stowe Periodic Table
+A Spiral Periodic Table
+ Mayan Periodic Table
+Families on the Periodic Table
Elements on the periodic table can be grouped into families bases on their chemical properties.
Each family has a specific name to differentiate it from the other families in the periodic table.
Elements in each family
react differently with
other elements.
The Periodic Table
Period
Group or family
PeriodGroup or Family
Metals, Nonmetals, Metalloids
There is a zig-zag or staircase line that divides the table.
Metals are on the left of the line, in blue.
Nonmetals are on the right of the line, in orange.
Metals, Nonmetals, Metalloids
Elements that border the stair case, shown in purple are the metalloids or semi-metals.
There is one important exception.
Aluminum is more metallic than not.
Metals
They are mostly solids at room temp.
What is one exception?
Properties of Metals
Metals are good conductors of heat and electricity
Metals are malleable
Metals are ductile
Metals have high tensile strength
Metals have luster
+ALKALI METALS
Group 1
Hydrogen is not a member, it is a non-metal
1 electron in the outer shell
Soft and silvery metals
Very reactive, esp. with water
Conduct electricity
Image: http://www.learner.org/interactives/periodic/groups2.html
+ Alkali metals and water
+All alkali metals react readily with water. The reaction becomes more vigorous down the group, and creates a lot of heat.
Reactions with water
The reaction also produces a gas that can be ignited by a lighted splint. What is this gas?
Li LiO
H H
OH H O H
-O H
-H H
Li +
Li +
This reaction creates alkaline hydroxide ions. This is why the group 1 elements are called the alkali metals.
+ + +
+Videos!
+ALKALINE EARTH METALS
Group 2
2 electrons in the outer shell
White and malleable
Conduct electricity
+Alkaline Earth Metals
They are less reactive than alkali metals, but they still react with water to produce H.
They are always combined in nature. Mg and Ca ions are found in seawater, and Ca is found in shells, which are made up of CaCO3.
+More on alkaline earth metalsProperties:
They are harder than alkali metals. They have a gray-white luster, but when they’re
exposed to air, they form a tough, thin oxide coating. Alloys with them generally have low densities.
Uses Mg is used in asbestos, which was a common insulator
until people discovered that it caused cancer. Ca is in slaked lime, which is used in plaster and
mortar.
+TRANSITION METALS
Groups in the middle
Good conductors of heat and electricity.
Some are used for jewelry.
The transition metals are able to put up to 32 electrons in their second to last shell.
Can bond with many elements in a variety of shapes.
Nonmetals
Nonmetals are the opposite of metals!
Some are solid, but many are gases, and Bromine is a liquid.
+
Properties of Nonmetals
Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. Nonmetals are poor conductors of heat and electricity
Nonmetals tend to be brittle
+BORON FAMILY
Group 3
3 electrons in the outer shell
Most are metals
Boron is a metalloid
+CARBON FAMILY
Group 4
4 electrons in the outer shell
Contains metals, metalloids, and a non-metal Carbon (C)
+NITROGEN FAMILY
Group 5
5 electrons in the outer shell
Can share electrons to form compounds
Contains metals, metalloids, and non-metals
+OXYGEN FAMILY
Group 6
6 electrons in the outer shell
Contains metals, metalloids, and non-metals
Reactive
+Halogens
Group 7
7 electrons in the outer shell
All are non-metals
Very reactive are often bonded with elements from Group 1
+Halogens
The halogen fluorine is the most reactive of the halogens in combining with other elements.
Iodine is the least reactive of the four nonmetals.
Chlorine is less reactive than fluorine, and bromine is less reactive than chlorine.
+Halogen compounds
Silver halides (e.g. silver chloride, silver bromide etc)
These are used in photographic paper. They are reduced by light and x-ray radiation to leave a silver photographic image.
Hydrogen halides (e.g. hydrogen chloride, hydrogen fluoride)
When these dissolve in water they make acids and will turn universal indicator red.
+Noble Gases
Group 8
Exist as gases
Non-metals
8 electrons in the outer shell = Full
Helium (He) has only 2 electrons in the outer shell = Full
Not reactive with other elements
+The noble gases were discovered and isolated in the 1890s by William Ramsey, Lord Rayleigh, and Morris Travers.
Discovery of argon
Each time he did the experiment, around 1% of the gas mixture did not react.Ramsay and his colleagues did further experiments and finally isolated a new element, which they called argon, from the Greek ‘argos’ meaning lazy or inactive.
Noble gases had actually been first discovered, but not recognized, by Henry Cavendish in 1766. He had passed a series of electric sparks through a mixture of air and oxygen, and collected the gases that were produced.
+ Discovery of the other noble gases
Once Ramsay had discovered argon, he realised that there was no place in the periodic table for it to fit. He predictedthat argon belonged to a whole new group of elements.
In 1885 Ramsay identified helium, and in 1888 he identified neon, krypton and xenon after studying liquid air.
Radon was discovered in 1900.
+Rare Earth Metals
Some are Radioactive
The rare earths are silver, silvery-white, or gray metals.
Conduct electricity
