5.3 The Periodic Table(Pages 194- 206)

VIDEOTED Ed - Solving the puzzle of the periodic table - Eric Rosado https://www.youtube.com/watch?v=O-48znAg7VE

Learning Goals

• I can describe how the periodic table is organized into groups and periods.

• I can explain how chemical symbols are used to identify elements.

• I can differentiate between metals and non-metals.

The Modern Periodic Table• The modern periodic table is organized

according to the atomic numbers of the elements.

• When the elements are arranged in order of increasing atomic number, there is a regular pattern in the properties of elements.

• The three main classes of elements are metals, non-metals, and metalloids.

Metals, Non-Metals and Metalloids

• Metals are usually solids at room temperature, shiny, good conductors, malleable and ductile.

• Nonmetals are usually gases or solids at room temperature, not shiny, poor conductors, brittle, and not ductile.

• Metalloids share properties of both metals and non-metals.

Groups and Periods• In the periodic table, a period is a horizontal row

of elements.• A group, or family, is a vertical column of

elements.• Elements that are in the same group have

similar properties. Four major groups of elements are the alkali metals, alkaline-earth metals, halogens and the noble gases.

What is an atomic mass?• The average mass of the naturally

occurring isotopes of an element.

VIDEO: Calculating Average Atomic Mass https://www.youtube.com/watch?v=HIToHoZGRSE

How Mendeleev Organized the Elements

• Mendeleev did not organize the elements according to subatomic particles since he did not know about them (they were discovered much later). He did try to organize them according their atomic mass.

• Mendeleev grouped elements with similar chemical properties. (In some cases this gives a different order than atomic mass, see for example: Tellurium versus Iodine!)

In 1871, scientists only knew of 66 elements. Mendeleev's periodic table looked like this:

Dashes unknown in 1871. represented elements.

3. How is the modern periodic table organized?

• The modern periodic table is organized according to increasing atomic number (the number of protons in the nucleus). The elements are also grouped according to electron shells (levels).

Usual, compact 18 column format.

Wide,32 column format.

What are synthetic elements? Where do you find the synthetic elements

in the periodic table?

• Synthetic elements are those elements that have been made by scientists.

• The synthetic elements in the periodic table are found amongst the elements that have atomic numbers more than 94.

• Plutonium is the largest naturally occurring element.

5. Metals vs. Non-MetalsMATERIAL STATE AT ROOM

TEMPERATUREAPPEARANCE CONDUCTIVITY MALLEABILITY

AND DUCTILITY

Metals Solid (except for mercury, which is a liquid)

Shiny Good conductors of heat and electricity

• Malleable • Ductile

Non-metals Some gases and some solids (except bromine, which is a liquid)

Not very shiny Poor conductors of heat and electricity

• Brittle • not ductile

Periods and Groups in the Periodic Table:

• The elements are arranged in horizontal rows and vertical columns.

• The correct name for each vertical column is a group.

• Elements in the same chemical family are located in the same group.

• The horizontal rows are called periods.• There are 18 groups and 7 periods in the periodic

table.

Lets take a look on - http://www.ptable.com

Chemical Family Elements and Symbols

Alkali Metals Hydrogen (H), Sodium (Na), Lithium (Li), Potassium (K)

Alkaline Earth Metals Beryllium (Be), Calcium (Ca), Magnesium (Mg), Strontium (Sr)

Halogens Fluorine (F), Bromine (Br), Astatine (At), Chlorine (Cl), Iodine (I)

Noble Gases Helium (He), Krypton (Kr), Radon (Rn), Neon (Ne), Xenon (Xe)

Lets take a look on - http://www.ptable.com

The Invention of Chemical Symbols:• The system of chemical symbols that we use

today was first proposed by the Swedish chemist Jons Jacob Berzelius.

• This system was accepted all around the world.

• The system provided symbols for all the known elements, and it showed how to create symbols for any new element that might be discovered later.

Language Name of Element SymbolEnglish hydrogen HFrench hydrogène HGerman wasserstoff HSpanish hidrogeno HChinese 氫 HKorean 수소 HPunjabi ਹਾਈਡਰ&ਜਨ HJapanese 水素 H

Five Rules to Determine the Symbols

Rule 1: The first letter of the name of the element.

Examples:Oxygen O Hydrogen H Carbon CFluorine F Nitrogen N Boron B

Rule 2: The first two letters of the name of the element.

Examples:

Krypton Kr Argon Ar Lithium LiNickel Ni Beryllium Be Xenon Xe

Rule 3: The first letter and one later letter of the name of the element.

Examples:

Manganese Mn Radon Rn Chlorine ClMagnesium Mg Rubidium Rb Astatine At

Some elements use symbolsfrom their Latin names.

Examples:Natrium (Na) SodiumKalium (K) PotassiumHydragyrum (Hg) MercuryAurum (Au) GoldArgentum (Ag) SilverFerrum (Fe) IronPlumbum (Pb) Lead

Later elements - named after countries, continents, scientists, place of discovery, or planets

Countries and Continents:Americium Am Europium Eu Germanium GePolonium Po Francium Fr

Place of discovery:Californium Cf Berkelium Bk

Name of scientists:Einsteinium Es Fermium Fe Copernicium CnRuthorfordium Rf Mendelevium Md

Name of a Planet:Plutonium Pu Uranium U Mercury Hg Neptunium Np

One is named after a colour: Indium (In) is named after the colour indigo!

Practice

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