Chemical reactivity

The full version will be presented Mon 31st July 2006

See you at the EXPO!

Last week our focus was;

1. Elements and compound

2. The work and thinking of the scientists who developed the periodic table (Hennig Brand, Johann Dobereiner, John Newlands and Dimitri Mendeleev)

The physical properties of both metals and non metals

(Groups, periods, atomic and mass numbers)

5. The reactivity of some elements

3

4

This week please think about the following;

1. the structure of the first 20 elements

2. The special stability of the inert gases

3. Why the other elements take part in chemical reactions

4. Ionic and covalent bonding

5. Learn the symbols/charges for some common ions.

Gp 1 Gp 2 Gp 3 Gp 4 Gp 5 Gp 6 Gp 7 Gp0

1 4

7 9 11 12 14 16 19 20

23 24 27 28 31 32 35.5 40

39 40

Essential Info

Useful linksUseful links    Who was Dmitri Mendeleev?Who was Dmitri Mendeleev? http://www.chemistry.co.nz/mendeleev.htmhttp://www.chemistry.co.nz/mendeleev.htm

A Quick look at the History of the Periodic TableA Quick look at the History of the Periodic Table http://periodictable.com/pages/AAE_History.htmlhttp://periodictable.com/pages/AAE_History.html

Periodic Table.comPeriodic Table.com http://periodictable.com/pages/AAE_PerTbl.htmlhttp://periodictable.com/pages/AAE_PerTbl.html

2 Dimensional Periodic Table2 Dimensional Periodic Table http://periodictable.com/pages/AAE_Flatprint.htmlhttp://periodictable.com/pages/AAE_Flatprint.html

3 Dimensional Periodic Table3 Dimensional Periodic Table http://periodictable.com/pages/1rotate.htmlhttp://periodictable.com/pages/1rotate.html

The Development of the Periodic TableThe Development of the Periodic Table http://www.chemsoc.org/viselements/pages/history_iii.htmlhttp://www.chemsoc.org/viselements/pages/history_iii.html

Web ElementsWeb Elements http://www.webelements.com/http://www.webelements.com/

Chemical Elements.comChemical Elements.com http://chemicalelements.com/http://chemicalelements.com/

Periodic Table of ElementsPeriodic Table of Elements http://environmentalchemistry.com/yogi/periodic/http://environmentalchemistry.com/yogi/periodic/

Period Table.com for StudentsPeriod Table.com for Studentshttp://periodictable.com/pages/AAE__studentHOME.htmlhttp://periodictable.com/pages/AAE__studentHOME.html

The basic stucture of the atom

NUCLEUS

Electrons in orbits

The nucleus contains protons and neutrons

The electrons spin around the nucleus in orbits

Essential Info

Essential Info

The electrons are found in orbits which spin around the nucleus

Generally as the orbits get further from the nucleus their size gets larger. They hold more electrons!

28

818

Atomic number = number of protons and number of electrons

Atomic Mass = number of protons and neutrons added together

Number of neutrons = Mass number - atomic number

Essential Info Na11

23

Some atom structures

I discussed atomic structure at this point

Na

Na23

11

Fluorine F19

9

ClF

Potassium K K39

19

You should be able to draw diagrams for the first twenty elements!!!!

Turn to page 497 and find out why atoms take partin chemical reactions

The p497 was mentioned in a Harry Potter film

It does not refer to any school text

Why do chemical reactions take place?

The inert gases are completely stable and DO NOT take part in chemical reactions

Atoms of other elements take part in chemical reactions so that they can become more stable. They would all like to have the same electron arrangements as the inert gases.

They can do this by either transferring electrons completely

or

by sharing electrons

Why does Mg react with O?

Mg is a group 2 metal. Its outer orbit has 2 electrons

It would like to become more like Ne. Ne is stable and has a full outer orbit.

O is a group 6 non metal. Its outer orbit has 6 electrons. It would also like a full outer orbit

By reacting together they can achieve this!

Mg O

Student guide to writing chemical formulae

;

Rules leading to correct formulaP

lease copy into your exercise books

1. Positive ions (cations) can join to negative ions (anions)

2. Positive ions usually form the first part of the name (99% cases)

3. If the formula is correct there is no overall charge

4. If you have more than one polyatomic ion it is placed inside brackets

Essential training ionsPositive ions Negative ions

+ 1 - 1

+2 - 2

+3 - 3

sodium Na+potassium K+hydrogen H+lithium Lisilver Ag+

fluoride F-

chloride Cl-

bromide Br-

hydroxide OH-nitrate NO3-hydrogencarbonate HCO3-

magnesium Mg2+calcium Ca2+barium Ba2+zinc Zn2+iron(11) Fe2+copper Cu2+

carbonate CO3oxide O2-sulphide S2-sulphate SO4sulphite SO3chromate CrO4

aluminium Al3+chromium Cr3+iron(111) Fe3+

nitride N3-

phosphate PO4

ammonium NH4+

IONS TABLE

http://www.eastmarinedrive.com/

Chemical Formulae 1.

CHARGESIONS NUMBERS

FORMULA

sodium fluoride

Chemical Formulae 2.

CHARGESIONS NUMBERS

FORMULA

magnesium fluoride

Chemical Formulae 3.

CHARGESIONS NUMBERS

FORMULA

silver hydroxide