CHEMICAL AND MATERIAL BEHAVIOURS CHEMISTRY

III.  CHEMICAL AND MATERIAL BEHAVIOURS (note that Chinese New Year Holiday is included, Jan. 23 to 30)       A.     Atom, Elements, and Compounds               1.     Chemical Alphabet               2.     Getting Sorted               3.     All Mixed Up               4.     Elements, Compounds, and Mixtures*       B.     Separating Mixtures               1.     Taking Salt from Underground               2.     Dissolving Rocks               3.     Sweet Tooth               4.     Pure Salt               5.     Super Solvents               6.     Distillation               7.     Better Boiling               8.     Major Crime Solving               9.     Chromatography       C.     TOPIC TEST REVIEW       D.     TOPIC TEST (week of March 26 to 30)

ELEMENT All the things are made up by tiny unit, element Element is the tiny unit of all the objects Element is the building block of the compounds Element song Element = simplest type of single substance Atom = smallest part of all matter/ smallest part of element Atom, element and compound element and compound

Atoms: the basic unit of compounds and elements

Carbon and hydrogen atoms Methane molecule Carbon and hydrogen atoms

Compound Compound = two or more elements combine together Molecules = at least two atoms join together Molecules sometimes means compounds

Formula of chemicals: Sulphur dioxide: SO2 Carbon dioxide: = CO2 Water = H2O Nitrogen = N2 Oxygen =O2 Sulphur dioxide: SO2

How can you tell that the following elements are molecules or not from their chemical formula? Oxygen Nitrogen Fluorine Bromine Chlorine Argon Helium Neon

How can you tell that the following elements are molecules or not from their chemical formula? Oxygen O2 Nitrogen N2 Fluorine F2 Bromine Br2 Chlorine Cl2 Argon Ar Helium He Neon Ne

copper sulphide

Properties of metal Good conductor Shiny Most of them can react with acid

Ag AC AC AB AC AB AC AB AB AC Mixture Element and compounds mix together Ag AC AC AB AC AB AC AB AB AC

Physical Reaction Definition: Changing the state of substance and the reaction is reversible. e.g. From solid changes as liquid and then from liquid changes as gas. From gas goes back as liquid and then changes as solid.

Chemical Reaction Irreversible reaction Colour will be changed after the reaction Gas will be given out (= evolved) Weight may change Heat is given out, temperature is changing. e.g. Magnesium reacts with Hydrochloric acid, forms Magnesium Chloride and Hydrogen.

Separation Methods