# The Periodic Table of Elements

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The Periodic Table of Elements

Periodic  Periodic Law  Periodic Table
Something periodic occurs at regular or at least generally predictable intervals Periodic law - physical and chemical properties of the elements are periodic functions of their atomic numbers Periodic Table of Elements – a table of the elements, arranged by atomic number, that shows the patterns in their properties; based on the periodic law Can you think of anything that is periodic?

Element A pure substance made up of one kind of atom that cannot be broken down into simpler substances by physical or chemical means 90 occur naturally on earth 25 were synthesized (made) by scientists Element Song

Dmitri Mendeleev In the 1860’s he devised a periodic table where the elements were ordered by their atomic masses He did this by grouping elements together according to their similarities Draft of Mendeleev's Periodic Table Image taken from:

Mendeleev’s Published Periodic Table of Elements
Why do you think there are question marks here? Image taken from:

Mendeleev’s Predictions
Although Mendeleev’s Periodic Table of Elements had missing elements or “gaps,” he was able to predict the characteristics of these missing elements because of Periodic Law. “Ekasilicon” Germanium Notice how Mendeleev’s predictions (orange column) were very accurate when compared to Germanium’s actual characteristics (green column) Date Predicted 1871 Date Discovered 1886 Atomic Mass 72 72.6 Density 5.5 g/cm3 5.47 g/cm3 Bonding Power 4 Color Dark Gray Grayish White

Henry Moseley Sample X-ray Spectra
In 1914, his work led to a revision of the periodic table by rearranging the elements by their atomic numbers He concluded that the number of protons in an atom is its atomic number Sample X-ray Spectra Image taken from:

Using the Periodic Table
The boxes that make up the periodic table contain a significant amount of information. To understand this information, it is necessary to refer to the periodic table’s key(s) 8 O Oxygen 15.999 Atomic Number (Number of protons) Element Symbol (Written with a capital letter or a capital followed by a lower case if two letters ) Element Name Atomic Mass (Rounded to a whole number, equals the number of protons and neutrons) Class Color Metal Non-Metal Metalloid State Room Temp.) Symbol Color Solid Liquid Gas What is Oxygen’s physical state of matter? Which class does Oxygen fall into?

3 Classes of Elements Using this as a guide, color code your periodic table to show the three classes. Start by highlighting the “zig-zag.” Class Color Metal Non-Metal Metalloid

What metal is not a solid
Metals Location Found on the left of the zigzag line/staircase on the periodic table (exception  Hydrogen) Chemical Properties Have few electrons in their outer energy level, thus lose electrons easily Physical Properties ductile, good conductors, malleable, shiny, most are room temperature 79 Au 11 Na 22.990 Image taken from: What metal is not a solid @ room temperature?

Atoms with Few Electrons in their Outer Energy Level
11 Na 22.990 Notice: only 1 electron in outer level + - + - 4 Be 9.012 Notice: only 2 electrons in outer level

Non-Metals Location Most found to the right of the zigzag line/staircase on the periodic table Chemical Properties Most have almost full outer energy levels, thus they tend to gain electrons; some have completely full outer level Physical Properties not ductile or malleable, not shiny, poor conductors, most are solid, but some are gas at room temperature 17 Cl 35.453 Image taken from: 16 S 32.066 Image taken from:

Atoms with Full or Almost Full Outer Energy Level
+ - 8 O 15.999     + - Notice: 2 electrons in outer level – FULL 2 He 4.003 + - Notice: 6 electrons in outer level – almost full Notice: 7 electrons in outer level – almost full 9 F 18.998

Metalloids Location Border the zigzag line/staircase on the periodic table Chemical Properties Most atoms have ½ (≈) complete set of electrons in outer level Physical Properties have properties of both metals and non-metals 14 Si 28.086 Image taken from: 5 B 10.811 Image taken from:

Atoms with ½ (≈) Complete Outer Energy Level
+ - Notice: only 4 electrons in outer level                     5 B 10.811 + - Notice: only 3 electrons in outer level 14 Si 28.086

Group (Family) Names Alkali Metals Alkaline Earth Metals Noble Gases
Boron Group Carbon Group Nitrogen Group Oxygen Group Halogens Transition Metals

Period and Groups When a column goes from top to bottom, it's called a group. The elements in a group have the same number of electrons in their outer orbital (Valence). When you look at a periodic table, each of the rows is considered to be a different period

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.

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 Color Light Blue Image:

ALKALINE EARTH METALS Group 2 2 electrons in the outer shell
White and malleable Reactive, but less than Alkali metals Conduct electricity Color Dark Green

TRANSITION METALS Groups 3- 12
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. Color Dark Blue

BORON FAMILY Group 13 3 electrons in the outer shell Most are metals
Boron is a metalloid Color Red

CARBON FAMILY Group 14 4 electrons in the outer shell
Contains metals, metalloids, and a non-metal Carbon (C) Color Yellow

NITROGEN FAMILY Group 15 5 electrons in the outer shell
Can share electrons to form compounds Contains metals, metalloids, and non-metals Color Bright Green

OXYGEN FAMILY Group 16 6 electrons in the outer shell
Contains metals, metalloids, and non-metals Reactive Color ORANGE

Halogens Group 17 7 electrons in the outer shell All are non-metals
Very reactive are often bonded with elements from Group 1 Color Yellow

Noble Gases Group 18 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 Color Grey

Rare Earth Metals Some are Radioactive
The rare earths are silver, silvery-white, or gray metals. Conduct electricity Color Violet