Properties of Materials Classifying Matter: Properties of Materials and Chemical Reactions

OUTCOME QUESTION(S): S1-2-07 S1-2-12 What properties classify elements as metals, nonmetals or metalloids? S1-2-12 How do you identify physical or chemical change and if a chemical reaction has taken place? Vocabulary & Concepts  State/Phase Lustre Ductility Malleability Solubility Conductivity Reactivity Combustibility Toxicity Precipitate Corrosion Oxidation Law of Conservation of Matter

Anything that has mass and takes up space, or volume. Matter: Anything that has mass and takes up space, or volume. Na NaCl NaCl + H2O NaCl + Pepper

A “staircase” on every Periodic Table separates the metals from the non-metals (with metalloids in between)

Can be qualitative or quantitative Physical properties Testing or measuring these traits will NOT change the original composition (what it is made of) Can be qualitative or quantitative quality quantity State/phase – solid, liquid or gas (at room temperature) Hardness – how easy it is to scratch or dent Viscosity – how easy it flows Melting point – unique temperature needed to change from solid into liquid Boiling point – unique temperature needed to change from liquid into gas

Other examples of Physical Properties: Lustre – shiny (opposite – dull) Malleability – how easy to bend or flatten (opposite – brittle) Ductility – how easy to pull into a wire Solubility – how well it dissolves in water Conductivity – how well it transfers heat/electricity Quantitative traits require a measurement – melting point Qualitative traits don’t need one – state

Trait describes if substance reacts chemically Chemical properties Trait describes if substance reacts chemically Testing or measuring these traits WILL change the original composition (will create something new) Reactivity – does it react quickly? Combustibility – does it ignite or burn? Corrosion – does it react with acids? Oxidation – does it react with air? Toxicity – does it react with the body? Testing a chemical property requires a chemical reaction that will alter what you test: wood  ash

What qualitative and quantitative properties can you use to describe metals, non-metals and metalloids?

(*) – there are some exceptions to these properties Property Metal Nonmetal Metalloid Lustre Malleable Ductile State (Rm Tp) Conduct heat Conduct electricity (*) – there are some exceptions to these properties shiny dull shiny* * * solid* s / l / g solid * semi

Anything that changes what it “looks like” NOT “what it is” Physical Change A change in shape or state of a substance - crushing, cutting, folding, smashing, melting, boiling… No evidence of a new material forming H O Anything that changes what it “looks like” NOT “what it is”

A chemical reaction has happened! Chemical change A change in the properties of a substance **Means a new substance is formed A chemical reaction has happened! Evidence of a chemical change (and chemical reaction): A change in colour A change in smell 3. Fizzing or bubbling (new gas being made)

Carbon Dioxide would put the flame out Testing for Gases Oxygen flame re-ignites or glows brighter Hydrogen gas explodes with a “pop” Carbon Dioxide would put the flame out

This new solid is called a precipitate 4. A new solid forms from a mixture of liquids or the mixture goes cloudy This new solid is called a precipitate A change in energy “Energy” could be light, heat, sound – think of the most obvious change in energy reaction – an EXPLOSION!

Testing the property can cause a… Physical properties Chemical properties Testing the property can cause a… Physical change Chemical change Δ colour Δ smell Δ energy Gas bubbles Precipitate State or shape NO Reaction Chemical Reaction Same substance with same properties New substance with new properties

Would the tree and the ash weigh the same? 1000 kg 1000 kg Would the tree and the ash weigh the same?

In any chemical reaction matter cannot be created or destroyed. Law of Conservation of Matter: In any chemical reaction matter cannot be created or destroyed. Atoms will rearrange to form new compounds – with new properties, but the number and type of atoms will not change during the reaction

CAN YOU ANSWER THESE QUESTIONS? S1-2-07 What properties classify elements as metals, nonmetals or metalloids? S1-2-12 How do you identify physical or chemical change and if a chemical reaction has taken place? Vocabulary & Concepts  State/Phase Lustre Ductility Malleability Solubility Conductivity Reactivity Combustibility Toxicity Precipitate Corrosion Oxidation Law of Conservation of Matter