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You live in a huge universe of matter. Because you cannot live without a sense of order. Our sorting techniques are usually based upon what we can detect with our senses. The characteristics of substances we can note with our physical senses are physical properties. Just as you can recognize your friends by their physical appearance, you can also recognize matter by its physical appearance and properties.
Physical Properties • a property that can be determined without changing the composition of the substance • Examples: colour, odor, density, melting point, boiling point
We have studied how to find the density of matter. • As you know, the equation for density is: • density = mass (grams) volume (mL or cm3) mass = density x volume volume = mass density
The following is a list of other ways of telling one form of matter from another. • ductility: The property displayed by certain metals that enables them to be drawn out into wires without breaking • malleability: The property displayed by certain metals that enables them to be hammered, rolled out, shaped, etc. without breaking
hardness: The property of an object that resists being crushed or deformed • brittleness: The property of an object that can easily be broken or crushed into smaller pieces under low pressure • conductivity: The property of metals, some metalloids, and ionic solutions that allow an electric current to pass through them • stateor phase: form – gas, liquid, solid – in which matter is found
solubility: The property of a substance that allows it to dissolve • melting point: The temperature at which a solid changes to a liquid • boiling point: The temperature at which a liquid changes to a gas
Compressibility – the property of a substance that allows it to be compressed Diffusion- The movement of one substance through another *** HIGH LOW ***
Chemical Properties of Matter • Chemical Properties: • A property of a substance that is observed when the substance undergoes a change in composition • active: reacts vigorously with other materials • inactive: does not react readily with other materials • inert: do not react under normal or ordinary conditions
Changes in Matter • Now that we have learned the fine points about physical and chemical properties, we are going to look at two kinds of changes – physical changes and chemical changes.
Physical Changes: • refers to a change in appearance not chemical composition of the substance • Examples: phase changes (s-> l -> g), crushing, grinding, dissolving (solubility)
Is tearing a piece of paper a physical change? • YES • Why or why not? • the composition of the matter does not change. It is a change in appearance only.
Is solid water (ice) changing into liquid water a physical change? • YES • Why or why not? • the composition of the matter does not change. It is a change in appearance only.
Chemical Changes • refers to a change in the composition of the matter......a new substance is formed • Examples: rusting of iron , combustion of a candle, burning of gasoline to run a car
There are some key signs that you can look for to determine whether or not a chemical change has occurred. These are as follows:
1. A gas is given off (BUBBLES) but not boiling 2. A precipitate (insoluble solid) is produced..... appears cloudy 3. Water is produced ..... Cobalt chloride paper turns from blue to pink 4. A color change could indicate a chemical change but also may indicate only a physical one 5. A temperature change may indicate a chemical change but can also indicate a physical one
STATES OF MATTER. 3 States of Matter: 1) Solid 2) Liquid 3) Gas
THE 4th STATE OF MATTER • WHAT????? • PLASMA • -defined as a gaseous mixture of positive ions and electrons • -Temperatures and densities range from relatively cool, less dense to hot and very dense
Plasma Cont’d On Earth , this mixture can only be created at very high temperatures in a lab, then carefully contained for use in objects like plasma TV’s The universe is made up of 99% plasma