Elements By T. M. Yeung 2000

Classification of Matters

Solid n Particles are packed close together in a regular pattern by strong attractive forces. n Particle vibrates about a fixed position. n Kinetic energy of particle is small.

Liquid n Particles are free to move. n Kinetic energy of particle is greater than that in solid state.

Gas n Particles have greater kinetic energy than in liquid state. n The distance between particles is very great.

solid liquid gas melting Freezing condensation boiling sublimation

Physical Changes n Melting n Freezing n Boiling n Condensation n Sublimation n…n…

Chemical Changes n Carbon Reduction –Iron oxide + Carbon --> Iron + Carbon dioxide n Electrolysis Electrolysis –Water --> Hydrogen + OxygenWater --> Hydrogen + Oxygen n Rusting of iron –Iron + Oxygen + Water --> Iron oxide (rust) n ….

Physical changes or Chemical changes?? n Breaking a glass bottle n Burning coal in air n Frying an egg n Knitting wool into a sweater. n Fractional distillation of petroleum n Destructive distillation of coal ê Physical change ê Chemical change ê Physical change ê Chemical change

Physical Properties ( 物理性質 ) n Length n Weight (Mass) n Colour n Density n Boiling Point n Resistance Resistance n ….

Metals are malleable & ductile

Chemical Properties ( 化學性質 ) n Sodium reacts with water to give hydrogen n Hydrogen burns with a ‘pop’ sound n Carbon dioxide turns limewater milky n ….

Classification of Elements by Physical States chlorine bromine iodine (gas) (liquid) (solid)

Liquid Metal & Non-metal

Examples of metal

Examples of non-metal

Classification of Elements MetalsNon-metals iron gold silver copper oxygen carbon hydrogen Semi-metal silicon boron

Semi-metals Boron ( 硼 ) Silicon( 矽 )

Classification of Matters

Symbols of Elements (1) n Hydrogen( 氫 ) Hydrogen n Boron ( 硼 ) Boron n Carbon( 碳 ) Carbon n Nitrogen( 氮 ) Nitrogen n Oxygen( 氧 ) Oxygen n Fluorine( 氟 ) Fluorine n Phosphorus( 磷 ) Phosphorus n Sulphur( 硫 ) Sulphur nHnH nBnB nCnC nNnN nOnO nFnF nPnP nSnS

Symbols of Elements (2) n Helium( 氦 ) Helium n Lithium( 鋰 ) Lithium n Beryllium( 鈹 ) Beryllium n Neon( 氖 ) Neon n Aluminium( 鋁 ) Aluminium n Silicon( 矽 ) Silicon n Argon( 氬 ) Argon n Calcium( 鈣 ) Calcium n He n Li n Be n Ne n Al n Si n Ar n Ca

Symbol of Elements (3) n Magnesium( 鎂 ) Magnesium n Chlorine( 氯 ) Chlorine n Mg n Cl

Symbols of Elements (4) n Sodium( 鈉 ) Sodium n Potassium( 鉀 ) Potassium n Na nKnK

First Twenty Elements Baptist Lui Ming Choi Secondary School Form Three Chemistry By T. M. Yeung 2000

Hydrogen (H) n The lightest gas in the world. n A fuel for heating and welding. n Town gas is a mixture of gases that contains hydrogen.

Helium (He) n The second lightest gas in the world. n The first member of noble gases. n Non-combustible and not reactive. n Filling balloon.

Lithium (Li) n First member of alkali metal. n Very reactive. n Lithium ion battery.

Beryllium (Be) Uses: n Aircraft n Missile n Spaceship

Boron (B) n Semi-metal n Making Pyrex Glass n Boric acid

Carbon (C) n Diamond –hard crystalline solid –non-conductor of electricity n Graphite –soft black solid –good conductor of electricity

Nitrogen (N) n Electric discharge in nitrogen. n Not reactive and incombustible gas. n Filling bag of fried potato chips. n Boiling point: -196 o C.

Oxygen (O) n Essential element of respiration. n Support combustion. n Fuel for rocket. n Boiling point: -183 o C

Fluorine (F) n Highly toxic gas. n Fluoride is added into drinking water to prevent tooth decay. n Long-term harmful effects is not yet known!?

Neon (Ne) n Second member of the noble gases. n Not reactive. n Neon sign.

Sodium (Na) n Very reactive metal. n Reacts with water to form hydrogen and sodium hydroxide. n It is kept under oil.

Magnesium (Mg) n Burns with brilliant bright light. n Magnesium hydroxide can be used to make antacid.

Aluminium (Al) n Light but strong n making aircraft body n making kitchen foil n making soft drink can n...

Silicon (Si) n Semi-metal. n Raw material to make semi-conductor. n Quartz is a mineral contains silicon dioxide.

Phosphorus (P) n Reactive non-metal. n Yellow phosphorus burns in air simultaneously. n It is kept under water. n Red phosphorus is used to make match. n...

Sulphur (S) n Non-metal n Yellow solid n Burns in air to give sulphur dioxide gas. n Making sulphuric acid. n...

Chlorine (Cl) n Second member of halogen. n Greenish-yellow gas. n Bleaching smell. n Toxic. n Sterilizing drinking water. n...

Argon (Ar) n Noble gas. n Chemically similar to neon. n Lighting.

Potassium (K) n Very reactive metal. n Making soap n Potassium feldspar n Chemical formula: KAlSi 3 O 8

Calcium (Ca) n Chalk cliff n Limestone, marble, sea shell and coral are made up of calcium carbonate.

References n Encarta 98 n Chemical Elements.com Periodic Table of the Elements – n The Elements in Alphabetical Order – ha.htm n Geological Periodic Table – table/index.html n Chemistry a modern view book 1A, Wilson