honors chemistry project-detailed description of the periodic table

8/13/2019 Honors Chemistry Project-Detailed Description of the Periodic Table

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The Periodic TableInformation

Ayma KhanHonors Chemistry


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Periodic Table Overview

Henry Moseley

DmitriMendeleev

A Russian Chemist called DmitriMendeleev was the first toconstruct the periodic table.

He listed the elements in severalvertical columns in order of

increasing mass number.In 1913, Henry Moseley, a youngBritish physicist determined thenuclear charge, called the atomicnumber, of the atoms of theelements.

He arranged the elements in a table

by order of atomic number.The horizontal rows of a periodic

table are called periods.The vertical columns are called

groups.


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Group:1 Alkali Metals Valence Electrons: 1The alkali metals include Sodium,Lithium,Potassium,Rubidium,Cesium and Francium.

SodiumSodium reacts violently with water and rapidly

with oxygen.

When electrons of these metals return to ground

level, energy is emitted and this energy has a

wavelength in the visible region:

Li red Na yellow K lilac Rb red

Cs blue

Physical PropertiesAll the Group 1 elements are silvery-

colored metals.

They are soft, and can be easily cut with

a knife to expose a shiny surface whichdulls on oxidation.

They have low melting and boiling

temperatures. They also have low

densities - Li, Na and K are less dense

than water.Alkali metals have color flames. When

the element is placed in a flame the heat

provides sufficient energy to promote the

outermost electron to a higher energy

level.


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Group:2 The Alkali Earth Metals Valence Electrons:2The alkali earth metals include berrylium,magnesium,calcium,strontium,barium and radium

Calcium

Magnesium

The alkaline earth metals are high in

the reactivity series of metals, but not

as high as the alkali metals of Group 1.

Physical PropertiesThe Group 2 elements are all

metals with silvery- white and shiny

color.

The metals of Group 2 have higher

melting points and are harder and

denser than sodium and potassium.

These properties are due largely to

the presence of two valence

electrons on each atom, which leadsto stronger metallic bonding than

occurs in Group1


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Group:24 The Transition Metals Valence Electron: 18

Tungsten

The transition elements readily

form alloys with themselves and

with other elements (e.g. acopper-tin alloy is used for

mirrors, brass is a copper-zinc

alloy). Tungsten, is used to

make tools and filaments in light

bulbs.

Physical PropertiesApart from Copper, the

transition metals are all white

lustrous metals.

They vary widely in

abundance (e.g. Iron, Fe, and

Titanium, Ti, are plentiful,

Scandium, Sc, is rare).

They have high meltingpoints and high densities.


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Group: 13 The Boron Group Valence Electron: 3The Boron Group includes boron,aluminum,gallium,indium and thallium

The mineral zinc blend,more commonly known as

sphalerite, in which both indium and thallium were

first discovered.

Gallium is one of the chief components of blue

LED.

Physical PropertiesAll the other members of Group 13 are soft,

silvery metals and boron is a non metallic grey

powder. Thallium develops a bluish tinge on

oxidation.

The influence of the non-metallic

character in this Group is reflected bythe softness of the metals.

The melting points of all the elementsare high, but the melting point of boronis much higher than that of beryllium inGroup 2, whereas the melting point ofaluminium is similar to that of magnesium

in Group 2. The densities of all the Group13 elements are higher than those ofGroup 2 elements.


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Group: 14 The Carbon Group Valence Electron: 4The carbon group includes carbon,silicon,germanium,tin and lead.

Carbon

Carbon exists in two

important allotropic forms,

diamond and graphite.

Silicon

Silicon is chemically

Physical Properties

Carbon is hard and transparent in the

form of diamond and a dull black color in

the form of graphite.

Silicon and germanium are dull grey orblack;

Tin and lead are a shiny grey color.

The change in bonding from covalent to

metallic down the Group causes a

decrease in melting point, boiling point,

heat of atomisation and first ionization

energy. At the same time, the increasing

metallic character causes a general

increase in density and conductivity.


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Group:15 The Nitrogen Group Valence Electron: 5The nitrogen family consists of nitrogen, phosphorus, arsenic, antimony and bismuth.

Nitrogen

Nitrogen and phosphorus are nonmetals.Arsenic and antimony are metalloids.Bismuth is a metal.

Phosphorous

Except for nitrogen, the elements aresolid at room temperature.

Physical PropertiesNitrogen is a colourless, odorless

gas. Phosphorus exists in white, red and

black solid forms.

Arsenic is found in yellow and greysolid forms

Antimony is found in a metallic oramorphous grey form.

Bismuth is a white, crystalline,brittle metal.


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Group :16 The Oxygen Group Valence Electron:6

Selenium

Tellu

rium

Sulfur is reactive in all its

forms. It burns in oxygen with

a blue flame to form sulfurdioxide, SO2, a un ent,

Physical Properties The first element of this

Group, oxygen, is the only gas,and is colorless and odorless.

Sulfur is a pale yellow, brittle solid.Selenium can have either an

amorphous or a crystalline structure.The amorphous form can be red or

black, and the crystalline form canbe red or grey.

Tellurium is a silvery-white colour with a

metallic lustre. Polonium is a naturally radioactive element.


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Group: 17 The Halogens Valence Electron:7The the halogen group includes Florine,chlorine,Bromine,Iodine and Astatine.

Florine

The most common uses of Fluorine are in the

Production of uranium, Air conditioning,

Refrigeration, Insecticide, Toothpaste, Added to

municipal water supplies and Teflon.

Physical PropertiesFlorine is a poisonous pale

yellow gas.

Chlorine is a poisonous

pale green gas.Bromine is a toxic and

caustic brown volatile

liquid.

Iodine is a shiny blacksolid which easily sublimes

to form a violet vapour on

heating.


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Group:0 The Noble Gases Valence Electrons:8The noble gases include Helium, Neon,Argon,Krypton and Xenon.

Argon

Helium is used by divers to dilute theoxygen they breathe.

Neon and argon are used for filling

discharge tubes.

Krypton

Physical PropertiesAs the name suggests, all

the elements in this Group

are gases.

Neon is colorless andodorless.


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Work Citation

http://www.rsc.org/chemsoc/visualelements/pages/data/intro_groupviii_data.htmlhttp://www.ausetute.com.au/trmetals.htmlhttp://www.rsc.org/chemsoc/visualelements/pages/data/int

ro_groupiv_data.htmlhttp://www.rsc.org/chemsoc/visualelements/pages/data/intro_groupv_data.htmlhttp://www.rsc.org/chemsoc/visualelements/pages/data/int

ro_groupvii_data.htmlPg 50-52

honors chemistry project-detailed description of the periodic table

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