The Periodic Table

MENDELEEV

Old image of periodic table

The following slides show the Structure

of the atom and how this relates to the Modern Peiodic

Table

The Atom

Nucleus Electron

Shell or Orbit

The structure of the atom

ELECTRON negative, mass nearly nothingPROTON

positive, same mass as neutron

(“1”)

NEUTRON neutral, same mass as proton (“1”)

Mass and atomic numberParticle Relative Mass Relative Charge

Proton 1 1

Neutron 1 0

Electron 0 -1

MASS NUMBER = number of protons + number of

neutrons

SYMBOL

PROTON NUMBER = number of protons (obviously)

How many protons, neutrons and electrons?

Mendeleev

Periodic tableThe periodic table arranges all the elements in groups according to their properties.

Horizontal rows are called PERIODS

Vertical columns are called GROUPS

H He

Li Be B C N O F Ne

NaMg

Al Si P S Cl Ar

K Ca Fe NiCu

Zn Br Kr

Ag I Xe

PtAu

Hg

The Periodic TableFact 1: Elements in the same group have the same number of electrons in the outer shell (this correspond to

their group number)

E.g. all group 1 metals have __ electron in their outer shell

These elements have __ electrons in their outer shell

These elements have __ electrons in their outer shells

H He

Li Be B C N O F Ne

NaMg

Al Si P S Cl Ar

K Ca Fe NiCu

Zn Br Kr

Ag I Xe

PtAu

Hg

The Periodic TableFact 2: As you move down through the periods an extra electron shell is

added:

E.g. Lithium has 3 electron in the configuration 2,1

Potassium has 19 electrons in the configuration __,__,__

Sodium has 11 electrons in the configuration 2,8,1

H He

Li Be B C N O F Ne

NaMg

Al Si P S Cl Ar

K Ca Fe NiCu

Zn Br Kr

Ag I Xe

PtAu

Hg

The Periodic TableFact 3: Most of the elements are metals:

These elements are metals

This line divides metals from non-metals

These elements are non-metals

H He

Li Be B C N O F Ne

NaMg

Al Si P S Cl Ar

K Ca Fe NiCu

Zn Br Kr

Ag I Xe

PtAu

Hg

The Periodic TableFact 4: (Most important) All of the elements in the same group have

similar PROPERTIES. This is how I thought of the periodic table in the

first place. This is called PERIODICITY.

E.g. consider the group 1 metals. They all:

1) Are soft

2) Can be easily cut with a knife

3) React with water

Group 0 – The Noble gasesHe

Ne

Ar

Kr

Xe

Rn

The Nobel gases

• The Nobel gases have full outer shells and they are found in group 0 of the periodic table. Helium, Neon, Argon, Krypton, Xenon and Radon.

Group 0

• These are the noble gases.

• They have complete electron shells.

• The electron shells are full.

• They are unreactive.

• They are inert.

• They do not react.

• They include, Helium, Neon, Argon, Krypton, Xenon and Radon

Group 0 – The Noble gasesSome facts…

1) All of the noble gases have a full outer shell, so they are very _____________2) They all have low melting and boiling points3) They exist as single atoms rather then diatomic molecules4) Helium is lighter then air and is used

in balloons and airships (as well as for talking in a silly voice)

5) Argon is used in light bulbs (because it is so unreactive) and argon , krypton and neon are used in fancy lights

The Atom Helium

ElectronProton

Neutron

Helium has two electrons, two protons and two neutrons

The Atom Neon

Protons

Neutrons

Electrons

Neon has ten electrons, ten protons and ten neutrons.

Group 1 – The alkali metals

Li

Na

K

Rb

Cs

Fr

The Alkali metals

• Lithium, Sodium and Potassium have one electron in their outer shell and this is why they are found in group one of the periodic table.

Group 1

• Lithium, sodium and potassium are all in group 1.

• They all have one electron in the outer shell.

• They are all metals.

• They react with group 7 to form metal halides.

Group 1 – The alkali metals

1) These metals all have ___ electron in their outer shell

Some facts…

2) Reactivity increases as you go _______ the group. This is because the electrons are further away from the _______ every time a _____ is added, so they are given up more easily.3) They all react with water to form an alkali (hence their name) and __________, e.g:

Words – down, one, shell, hydrogen, nucleus

Potassium + water potassium hydroxide + hydrogen

2K(s) + 2H2O(l) 2KOH(aq) + H2(g)

The Atom Lithium

Protons

Neutrons

Electrons

The Atom Sodium

Protons

Neutrons

Electrons

Sodium has eleven electrons, eleven protons and twelve neutrons.

Group 7 – The halogens

F

Cl

Br

I

At

The Halogens

• Fluorine, Chlorine, Bromine and Iodine are the Halogens and they all have seven electrons in their outer shell. This is why they are found in group 7 of the periodic table.

Group 7

• Fluorine ,Chlorine, Bromine and Iodine.

• They all have 7 electrons in their outer shell.

• They are all coloured.

• They form metal halides with group 1 metals.

Group 7 – The HalogensSome facts…

1) Reactivity DECREASES as you go down the group

Decreasin

greactivit

y

(This is because the electrons are further away from the nucleus and so any extra electrons aren’t attracted as much).

2) They exist as diatomic molecules (so that they both have a full outer shell):

Cl Cl

3) Because of this fluorine and chlorine are liquid at room temperature and bromine is a gas

HalogensName

Fluorine

Colour

Pale Yellow

State

Gas

M.P.

-220

B.P.

-188

Chlorine Green Gas -101 -34

Bromine Brown Liquid -7 59

Iodine Slate grey

Solid 114 184

The Atom Fluorine

Protons

Neutrons

Electrons

Fluorine has nine electrons, nine protons and ten neutrons.

Uses of the Halogens

• Fluorine is put into water supplies to kill harmful bacteria and to help keep teeth healthy.

• Chlorine is used in swimming pools to bacteria in the water.

• Bromine is used in pesticides. Silver bromide is used in photography.

• Iodine is an antiseptic on cuts and grazes.

The halogens – some reactions1) Halogen + metal:

Na

+

Cl

-

Na Cl

+

2) Halogen + non-metal:

H Cl+ Cl H

Halogen + metal ionic salt

Halogen + non-metal covalent molecule

Reactions

• Sodium and Chlorine react to form

• Sodium Chloride.

• Iron and Chlorine react to form • Iron Chloride.

• 2Na + Cl2 2NaCl.

• Fe + Cl2 FeCl2.

Displacement

• Fluorine can displace Chlorine, Bromine and Iodine.

F Cl Br I

Displacement

• Chlorine can displace Bromine and Iodine but it cannot displace Fluorine

Cl Br I F

Displacement

• Bromine can displace Iodine but it cannot displace Fluorine or Chlorine

Br I F Cl

Displacement

• Iodine cannot displace Iodine Fluorine, Chlorine or Bromine

I F Cl Br

Fluorine reacts with sodium chloride. Which equation is

correctly shows this reaction?

• F2 + 2Na 2NaF

• F + Na NaF

• 2F + 2Na 2NaF

Which will displace?

• 2NaF + Cl2 Yes or No

• 2NaBr + Cl2 Yes or No

• 2KI + I2 Yes or No

• 2LiCl + I2 Yes or No

• 2NaBr + I2 Yes or No

• 2NaBr + F2 Yes or No

• Cl2 + 2NaBr Yes or No