Observing Matter Chemistry 11 Chapter 1

Chemistry Begins with questions such as: Why does octane burn but heptane explode? How can we separate oil and water? Why does salt dissolve in water? Why does iron rust? Continues with observation of matter and an attempt to qualify and quantify changes as either Chemical Physical

States of Matter Solid – atoms exist in a rigid structure with definite size and shape Solid – atoms exist in a rigid structure with definite size and shape Liquid – there are weak links between atoms but they are able to move past each other and will fill the container Liquid – there are weak links between atoms but they are able to move past each other and will fill the container Gas – atoms move past each other and fill space Gas – atoms move past each other and fill space Plasma – atoms have become ionized Plasma – atoms have become ionized

Physical Properties Qualitative Qualitative State State Colour Colour Odour Odour Crystal shape Crystal shape Malleability Malleability Ductility Ductility Hardness Hardness Brittleness Brittleness Quantitative Quantitative Melting Point Boiling Point Density Solubility Electrical conductivity Thermal conductivity

Chemical Properties Reactivity with water Reactivity with water Reactivity with air (oxygen, nitrogen) Reactivity with air (oxygen, nitrogen) Reactivity with acids Reactivity with acids Reactivity with bases Reactivity with bases Reactivity with pure substances Reactivity with pure substances Toxicity Toxicity Decomposition Decomposition

Mixture or Solution Mixtures Mixtures Can be heterogeneous or homogenous Can be heterogeneous or homogenous “Easily” separated “Easily” separated May be translucent but not transparent May be translucent but not transparent Solutions Solutions Must be homogenous More difficult to separate (often requires physical or chemical change) Will be transparent (can have colour)

Pure Substances, Elements and Compounds Pure Substances Pure Substances Composed of only one type of element or compound Composed of only one type of element or compound Elements Elements Made of only one type of atom (i.e. oxygen gas, carbon, mercury, etc) Made of only one type of atom (i.e. oxygen gas, carbon, mercury, etc) Compounds Compounds Made of more than one type of atom (i.e. water, carbon dioxide, sodium chloride, etc) Made of more than one type of atom (i.e. water, carbon dioxide, sodium chloride, etc)