GENCHEM 1 | 0102 • V12
Lesson 2: Properties of Matter [UNIT 1]
General Properties of Matter are characteristics of matter that are present in all kinds of matter.
[ Mass and Volume are properties that are common to all forms of matter. ]
Specific property of matter : when a property is observable only in a particular kind of matter.
( The fundamental properties that are used to describe matter are mass, volume, weight, density, and specific gravity. )
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Mass refers to the amount of matter in an object.
• describes how much matter comprises a material.
• Mass is usually expressed in grams (g) or kilograms (kg). (the more matter is present is an object means the greater its mass)
Weight is the measure of force that acts on an object.
• expressed as the amount of matter (mass) multiplied by the gravitational force that acts on it.
• Weight is expressed in newtons (N).
[ Mass and weight are often interchangeable, but these are two different quantities. ]
Volume the amount of space occupied by matter.
• volumes of liquids r often expressed in millimeters (mL) or liters (L).
• volumes of solids r often expressed in cubic centimeters (cm³) or cubic meters (m³).
Density is a physical property that expresses the ratio between mass and volume.
• since it is a ratio between M and V, it is often expressed in kilograms per cubic meter (kg/m³) or grams per cubic centimeter (g/cm³).
• also tells how compact an object is. (object w greater mass has more compact particles than lighter ones, therefore, a massive object that occupies less space also possesses a higher density.)
Table 1.2.2. in Messenger
Specific Gravity is the ratio of a substance's density to a standard substance. (This is the reason why it is also known as relative density.)
• since specific gravity is a ratio between two densities, it is a dimensionless quantity wherein no physical dimension is assigned.
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Physical Properties are qualities that are readily observable or measurable without changing the matter's composition.
• are often used to describe/observe matter.
(other example of physical properties are melting point, freezing point, solubility, and metallic properties.)
Melting Point : the temperature at which a solid matter changes to liquid.
• As solids absorb heat energy, its temperature increases, causing its particles to move faster and dissociate from one another. (This dissociation leads to a phase change known as melting.)
Freezing Point : the temperature at which a liquid turns into a solid matter.
• Liquids tend to be solid when cooled, if it is cooled, its particles slow down as they lose kinetic energy due to lower temperature.
Table 1.2.3. in Messenger
Boiling Point : the temperature at which liquid vaporizes.
• When liquid is heated, its particles absorb the heat energy. The gain in kinetic energy of particles allows them to break away from one another and move faster in random directions. (This results in vaporization or the change from a liquid state to a gaseous state / vapor.)
Solubility : the ability of a solute to dissolve in a given solvent.
• Materials that mix well form a homogeneous phase wherein the substance in a lesser amount (solute) dissolves in another substance of greater amount (solvent).
• Different terms are used to describe the solubility of a certain material.
⤷ high soluble if it dissolves easily in a solvent.
× For the case of fluids like liquids & gases, substances are said to be miscible if they mix well together.
× Substances that do not completely mix are said to be partially soluble or partially miscible.
⤷ insoluble or immiscible if it does not dissolve at all in a given solvent.
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Metallic Properties are qualities that are observed specifically in metals.
• these properties set metals apart from other materials.
(some metallic properties are conductivity, malleability, and ductility)
Conductivity : the ability of a material to allow heat or electric charges to pass through easily.
Malleability : metal can be flattened into thin sheets.
Ductility : metal can be easily drawn into wires.
(This property makes metal a good material for electrical wirings and components)
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Chemical Properties are characteristics that can only be seem when the chemical identity of a material is altered.
• these properties only become evident when a material undergoes a chemical change.
(some chemical properties are biodegradability, combustibility, flammability, and reactivity)
Biodegradability : the capacity of a material to decompose through the actions of microorganisms.
• may only be observed when a material undergoes decomposition.
Table 1.2.4. in Messenger
Flammability : is the ability of a combustible material to catch flame easily.
Combustibility : the ability of a material to combust or burn.
[ Terms “flammable“ and “combustible“ are often used to describe the ability of a material to burn. These properties may only be observed when materials are subjected to combustion. ]
Reactivity : the tendency of a substance to undergo a chemical reaction.
• reactivity depends on its chemical structure.
× (the most reactive element is fluorine as it easily combines with another element to form a compound.)
× (the no to little reactivity elements are noble gases.)
× the least reactive element = helium, least reactive metal = platinum
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Intensive vs. Extensive Properties of Matter
— physical properties of matter may be further classified as intensive or extensive.
Intensive properties : do not depend on the amount of matter.
(Ex. the color of an object does mot depend on its amount.)
Extensive properties : depend on the amount of matter.
• these characteristics changes when the amount of matter is decreased or increased.