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Matter & Change
What is matter?
Matter is anything that has mass
and takes up space.
Quantifying Matter – Measuring Matter
Mass – measure of the amount of matter.
Volume - amount of three-dimensional space an object occupies.
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States of Matter
The physical forms in which a
substance can exist
Bose-Einstein Condensate
Solid
Liquid
Gas
Plasma
The Different States of Matter
State Example Characteristics
Solid Definite volume & definite shape
Liquid Definite volume; takes shape of container
Gas No definite shape or volume
Plasma Exists at high temps;No definite shape or volume
States of Matter on a Molecular Level
State What is happening at the molecular level?
Solid
Liquid
Gas
Molecules are close together, have strong attractions for each other, are locked into position, and only have vibrational motion
Molecules are moving slowly, are close to each other, have attractions to each other that are constantly forming and breaking
Molecules are in constant rapid motion, are widely separated, are not attracted to each other, and they bounce off each other when they collide
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Phase Changes
Solid Liquid GasMelting Evaporation
ç CondensationFreezing
Sublimation
çDeposition
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Phase Changes
S
O
L
I
D
Gas
Sublimation
çDeposition
Physical Property vs Chemical Property
Physical Property - property that can be observed or measured without changing the identity of the substance
Chemical Property - property that cannot be observed without permanently altering the substance's identity
Physical Properties
Examples of Physical Properties:
1. Density 2. Volume 3. Temperature4. Length5. Pressure
6. Melting Point 7. Boiling Point8. Solubility9. Concentration 10. Energy 11. specific heat
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Chemical Properties
Examples of Chemical Properties:
1. Flammability 2. Toxicity 3. Reactivity4. pH
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Physical Change vs Chemical Change
Physical Change - a change in a substance that does not involve a change in the identity of the substance. The substance may look different but it still remains the same
Chemical Property - a change that occurs when one or more substances change into entirely new substances with different properties
Physical Changes
Examples of Physical Changes:
1. Change of state or phase (such as from solid to liquid) 2. Dissolving a substance3. Absorption of water into a towel 4. Crumpling a piece of paper 5. Pulling copper into a thin wire - a change of shape, but not a change of composition 6. Cutting a material such as wood 7. Ripping a piece of tin foil
Chemical Changes
Examples of chemical changes:1. Burning anything. (Not Melting or Boiling)2. Mixing an acid with a base, producing water and a salt. 3. Photosynthesis - a process in which carbon dioxide and water are changed into sugars by plants.4. Decomposition of organic matter (for example, rotting food, food going bad).
Evidence of aChemical Change
1. Can not get back to the original substance2. Change of color (for example, iron to reddish-brown when iron rusts). Note: Color change is typically a good indication of a chemical change but one should look for other evidence as well.
3. Release of odor4. Release/absorption of heat (increase or decrease of temp) 5. Change of form (ie: burning paper)6. Release /absorption of energy (light or sound) 7. Formation of gases (bubbles or smoke). 8. Formation of a precipitate (solid particles).
Examples of Chemical Changes
Building Blocks of Matter
Element - any substance that cannot be broken down into simpler substances
Found on the periodic table.
Building Blocks of Matter
Atom - smallest particle of an element
Building Blocks of Matter
Compound - a substance made from two or more different elements that are chemically combined.
Building Blocks of Matter
Molecule – a collection of elements bonded together that behave as a unit.
They do not need to contain two different elements.
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Building Blocks of Matter
Diatomic Molecules – Molecules that are composed of two atoms.
Eight elements exist in the diatomic state in the liquid and solid states:
H2, N2, O2, F2, Cl2, Br2, I2, and At2
Pure Substances
Pure Substance - a substance that always has the same composition
Examples: elements, molecules, and compounds
Properties of Pure Substances
•Every sample of a pure substance has exactly the same characteristic properties.
•Every sample of a pure substance has exactly the same composition.
Mixtures
Mixture - A substance composed of two or more elements or compounds that are physically mixed together but not chemically combined.
Mixtures are physically combined and can be separated
Mixtures are not only liquid. There can be solid, liquid, and gas mixtures
Types of Mixtures
Homogeneous mixture – a mixture in which the composition is uniform throughout
Examples: Salt water, air, alloys, carbonated water
Heterogeneous mixture – a mixture that is not uniform throughout.
Examples: Sand and water, salad dressing, oil and water
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Alloys
Metallic Alloys – a homogeneous mixture of two or more metals
Carbon Steel - Iron with Carbon
Stainless Steel - Iron with Chromium
Brass - Copper with Zinc
Bronze - Copper with Tin
Pewter - Tin with Copper
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Alloys
Aluminum - Aluminum with various elements
Silver - Silver with Copper
Gold - Gold with Silver and/or Copper 24 karat = 24 parts of gold (very soft) 22 karat = 22 parts gold : 2 parts Silver/Copper 18 karat = 18 parts gold : 6 parts Silver/Copper 14 karat = 14 parts gold : 10 parts Silver/Copper 10 karat = 10 parts gold : 14 parts Silver/Copper
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Homogeneous or Heterogeneous?
HomogeneousHomogeneous
HomogeneousHomogeneous
HeterogeneousHeterogeneousHeterogeneousHeterogeneous
HeterogeneousHeterogeneousHomogeneousHomogeneous
Classification of Matter
Matter
Can it be separated?
Mixtures Pure Substances
Is the composition uniform?
Homogeneous Heterogeneous
Yes No
Can it be broken down ordinarily?
Compound Element
Yes No Yes No
Products & Reactants
Reactants - substances that react in a chemical reaction. Shown on the left of a chemical equation
Products - substances that are formed as a result of a chemical reaction. Shown on the right of a chemical equation
carboncarbon + + oxygenoxygen carbon dioxidecarbon dioxide
CC + + OO22 COCO22
reactantsreactants yieldyield productsproducts
Carbon reacts with oxygen to yield carbon dioxide.
Chemical Reactions
Chemical reaction - process by which one or more substances change to produce one or more different substances.
Examples:
NaOH + HCl NaCl + H2O
CH4 + O2 H2O + CO2
Gummy Bear Demonstration
KClO3 + Gummy Bear CO2 + KCl + H2O
Potassium Chlorate + Gummy Bear
Carbon Dioxide + Potassium Chloride + Water
•What are the reactants?
• What are the products?
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Separation Techniques
Mixtures can be separated into their individual components.
Following are various separation methods...
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Separation Techniques
Gravitational Filtration - uses gravity and filter paper to separate heterogeneous mixtures of liquids and solids.
Separation Techniques
Magnetism- used to separate magnetic matter from non-magnetic matter.
Usually used to separate solid magnetic material from solid non-magnetic material.
Separation Techniques
Electrolysis - use of electricity to separate compounds.
Separation Techniques
Vacuum Filtration - uses vacuum suction to separate heterogeneous mixtures of solids & liquids.
Separation Techniques
Separatory Funnel - used to separate heterogeneous mixtures of 2 or more liquids.
Separation Techniques
Distillation- uses different boiling points to separate homogeneous solutions formed from 2 or more liquids.
Separation Techniques
Centrifuge- uses rapid spinning to separate solids from liquids.
Separation Techniques
Chromatography- used to separate homogeneous mixtures through the use of a solvent & a medium.
Separation Techniques
Recrystallization- a separation technique in which the temperature of a solvent is increased to allow the solute to dissolve and then allowed to cool, which promotes the formation of solute crystals
Separation Techniques
Crystallization- separates a solid that is dissolved in a liquid through evaporation. The liquid evaporates & the solid recrystallizes.
