HKCEE CHEMISTRY

INTRODUCTION

MATTER (substance)

THE THREE STATES OF MATTERGas

Solid

Liquid(solution)

ATMOSPHERE

EARTH

OCEAN

\

A beaker of muddy water

Air - gas (g)

Sea water – solution (aq)

Water – liquid (l) Mud /sand –

solid (s)

MATTER (classification)

EL EM ENT COM POUND

PURE SUBSTANCE M IXTURE

M ATTER

ELEMENT: simplest substance (112 known)COMPOUND:two or more elements joined together

chemicallyMIXTURE: two or more substances

(not joined together chemically)

MATTER

Q1 State some substances present inthe ocean (solution/ liquid), the atmosphere (gas)the earth (solid)

Q2 Is the substance stated above an element(e), a compound( c) or a mixture(m)?

Q3 What is the substance made of?

MATTER(LIQUID/ SOLUTION)

(element) (mixture) (compound)mercury Sea water detergent

orange juice waterbeer alcoholcoffeetearpetroleum petrol

MATTER(GAS)

(element) (mixture) (compound)oxygen Air carbon dioxidenitrogen water vapourhydrogenozone

MATTER(SOLID)

(element) (mixture) (compound)gold steel Sandsilver tin-plated iron plasticcopper bone icealuminium bronze mudiron rusttin limestone

MATTER(What is the substance made of?)

1 Mixture (substance a?.. substance b?..)

2 Compound(element x?element y? element ..)

3 Element(Atom 1? Atom 2? Atom..)

(4) Atom(? ? ?..)

MIXTURE – separation? MIXTURE PURE

SUBSTANCES Example: Muddy sea water Separate Air (pumping, sucking) Separate Mud from Water (filtering) Separate Water from Sea water

(distillation) Separate Salt from Sea Water

(evaporation, crystallization, filtration)

COMPOUND – separation? COMPOUND ELEMENTS Example: WATER Electrolysis of water At the ANODE: oxygen At the CATHODE: hydrogen

Test for oxygen? Test for hydrogen?

Change (burning a match)

change

Wood Ash/ soot

(Substance A) (Substance B)

Change(1)

SUBSTANCEB

CHANGE

WHAT is substance A / substance B made of?

WHAT are the properties of the substance (A / B)? (Physical properties and Chemical properties)

SUBSTANC

EA

Change (2)

SUBSTANCEB

CHANGE

Q1 WHAT is the CHANGE? (Physical change or Chemical change /Chemical Reaction)

Q2 WHAT do you OBSERVE? (DESCRIBE the observation)

Q3 EXPLAIN WHY the CHANGE occurred.

SUBSTANC

EA

Change (3)

(MACROSCOPIC WORLD)

(MICROSCOPIC WORLD)

Wood (A)changes to

Ash(B)

Rearrangement of atoms of A and B

(particles in A and B)(A B)

OBSERVATION

EXPLANATION

(A B)

Change (4) - PHYSICAL CHANGE

No NEW substance is formed.

(only change in physical state of the substance)

-Boiling l g

-Condensing g l

-Melting s l

-Freezing l s

-Sublimation s g

Change(5)- CHEMICAL CHANGE

NEW substance(s) is(are) formed.

(Change in STRUCTURE and PROPERTIES)

-Burning

-Rusting

Property (1) - PHYSICAL Property

Can be Measured / observed

(without change to new substance)

-Colour Smell Taste

-Physical state (at room temperature)

-Density

-Melting point / Boiling point

-(Conductor of electricity)

-(Solubility in water)

Property (2) - Chemical Property

Chemical reactions

(able to change to new substances)

-React with oxygen in air (burning)

-React with oxygen in air (oxidation)

-React with water (..)

-React with ..

Particles (microscopic world)

n,p,e

+

ION

-

MOLECULE

(stable)

ATOM

ATOMB

ATOMA

CATION

(stable)

ANION

(stable)

Sub-atomic Particles

NEUTRONS(n)

PROTONS(p)

ELECTRONS(e)

ATOM

MODELS OF SUBSTANCES

*ARE NOT REAL

*HELPS US TO VISUALIZE THE ARRANGEMENT OF PARTICLES OF THE MICROSCOPIC WORLD

EXAMPLES:

-MODEL OF ATOM

-MODEL OF MOLECULE

-MODEL OF ELEMENT

-MODEL OF COMPOUND

CHEMISTRY OF PURE SUBSTANCE

(MACROSCOPIC WORLD)

(MICROSCOPIC WORLD)

ELEMENTCOMPOUND

ATOMSIONS

MOLECULES

SAMPLES

of substances

MODELS

(of atomic particles)

EXPERIMENT

EXPLANATION

PURE SUBSTANCE (CLASSIFICATION)

M ETAL(M )

NON-M ETAL(N)

EL EM ENT

COVAL ENT(N1-N2-...)

IONIC(M 1 N2)

COM POUND

PURE SUBSTANCE

ELEMENT: METALSNON-METALS(SEMI-METALS)

COMPOUND: IONIC (metal & non-metal)COVALENT(non-metals only)

PURE SUBSTANCE (MICROSCOPIC WORLD)

ATOM M OL ECUL E

EL EM ENT

COVAL ENT(M OL ECUL E)

IONIC(CATION, ANION)

COM POUND

PURE SUBSTANCE

ELEMENT: ATOMS (of the same type)MOLECULES (of same type of atoms)

COMPOUND: IONIC COMPOUND (CATIONS & ANIONS from metals and non-metals) COVALENT COMPOUND (MOLECULES of different non-

metal atoms)