Aims

Class work 26 June 2007Structures and Bonding

Atomic StructureLO’s• What makes up atoms?

Write it down!! Page 42© C Meyer

Chemistry Unit 2 Sections

Structures Structures and bonding and properties How

much?

© C Meyer

Chemistry Unit 2 Sections

Rates of Energy and Acids, alkalis

reaction reactions Electrolysis and salts

© C Meyer

Examination

• NOT like year 10 with 3 lots of modules taken through the year

• 3 exams taken in June 2008• All 45 minutes• NOT multiple choice – ALL short

answer

All• Know the particles that make up an

atom• Know the charges of the particles• Define atomic numberMost• Explain why atoms are electrically

neutralSome• Understand how the elements are

ordered in the periodic table

Aims

• The periodic table shows all the elements. Elements are made up from 3 small particles.

In back – 30 sec• How would you draw the structure

of an element?• What are the names and charges

of the particles?

What makes up atoms?

• The middle (nucleus) of an atom is made up from protons (+) and neutrons (no charge)

• Electrons (-) whizz around the nucleus• There are the same number of electrons

and protons (+’s cancel out –’s)

Atomic Structure

What makes up atoms?

Think 3D

What makes up atoms?

What makes up atoms?Title – Atomic Structure

• Draw a diagram of an atom• Label a neutron, proton, electron

and nucleus• Also give their charge

neutron = 0

proton = +1

electron= -1

m5

nucleus= proton

+ neutron

What is atomic number?

Atomic number = the number of protons in an atom

proton

electron neutron

heliumnucleus

These are the particles in a helium atom

What is the atomic number of helium?

Properties and atomic number

particleparticle chargecharge relative massrelative mass

proton +1 1

neutron 0 1

electron -1 0.0005

Scientists discovered that the properties of elements seemed to depend on atomic number.

What is the atomic number of an element?

Atoms contain three types of particles:

Number of protons

Copy Tablem6

• There are the same number of electrons and protons (+’s cancel out –’s)

• Atoms have NO charge

What makes up atoms?

A few sums• +6 – 6 =• -12 + 12

=• 48 – 48 =

0

00

m8

A few more sums• 6 protons and 6 electrons =• 12 electrons and 12 protons

=• 36 protons and 36 electrons

=

000

ActivityDrag the statements at the top onto the correct

side of the table

ActivityDrag the statements at the top onto the correct

side of the table

• Take one colour A4 card• Fold in half length ways, open out• Fold in half width ways, open out• Fold 2 ends into middle fold• You have 8 rectangles• Repeat with 2 more pieces of

different coloured card to the first• Cut out rectangles so you have 24

pieces of card (8 one colour, 16 another)

What makes up atoms?

• Put a different element name on each card, along with its symbol, number of protons and number of electrons. Metals on 1 colour, others on other

What makes up atoms?

SodiumNa

MetalProtons = 11Electron = 11

Name Metal Atomic number

Name Metal Atomic number

Aluminium

Yes 13 Lithium Yes 3

Argon 18 Magnesium Yes 12

Beryllium Yes 4 Neon 10

Boron 5 Nitrogen 7

Calcium Yes 20 Oxygen 8

Carbon 6 Phosphorus 15

Chlorine 17 Potassium Yes 19

Fluorine 9 Silicon 14

Helium 2 Sodium Yes 11

Hydrogen 1 Sulphur 16

CarbonC

Non MetalProtons = 6Electron = 6

• Finish off your 20 cards

• Will need to use them next lesson

Homework

• Arrange you cards in an order you pick eg alphabetical

• See how many different ways you can re-arrange the cards

What makes up atoms?

• IN the periodic table are arranged in atomic/proton number order – BUT why in blocks?

m1

Atomic number and patterns

KH Li NaBe Mg Al PN O S ClF Ne ArSiHe B C

reactive metalsunreactive gases

reactive gases

When scientists arranged elements in order of increasing atomic number they found patterns in their properties.

Demo Li/Na

Positions of similar elements

How many elements are there from one reactive metal to the next?

How many elements are there from one reactive gas to the next?

KH Li NaBe Mg Al PN O S ClF Ne ArSiHe B C

191 3 114 12 13 157 8 16 179 10 18142 5 6

8

8

Compare the positions of similar elements.

reactive gases reactive metals

Arranging elements

Arranging these strips in rows…

Divide the elements at set intervals, arrange them according to their properties and what patterns do you see?

cut here

KH Li NaBe Mg Al PN O S ClF Ne ArSiHe B C

191 3 114 12 13 157 8 16 179 10 18142 5 6

cut herecut here

NaMg Al P S Cl ArSi

H He

Li Be N O F NeB C

K

Arranging elements

K

He

Al P SSiMgNa ArCl

Be N OB CLi NeF

When elements are arranged according to their properties what patterns do you see and what element is missing?

reactive metals

unreactive gases

reactive gases

Similar elements go into the same columns.

Hydrogen is an exception. This reactive gas is best positioned above the reactive metals.

Hhydrogen is a special case

Tidy UP!!!

• Stack items tidily• Clean up bench/floor• Sit down when finished

• What mostly makes up atoms?

• What stops electrons whizzing off into space?

• Which bit of the atom does the chemistry?

• Which bit of the atom does the radioactivity come from?

What have I learnt?

Space

Electrostatic attraction

Electrons

Nucleausm1

The End