Chen 12 Lesson 1

Matter

is anything that occupies space and has mass.is anything that occupies space and has mass.

atom

smallest unit of an element.

molecule

sthe smallest particle of a substance that retains all the properties of that substance.

substance

is a form of matter that has a definite composition and distinct properties.

element

substance that cannot be separated into simpler substances by chemical means

compund

substance composed of atoms of two or more elements chemically united in fixed proportions

mixture

combination of two or more substances in which the substances retain their distinct identities.

homogeneous mixture

the composition of the mixture is the same throughout

heterogeneous mixture

the composition is not uniform in a mixture

physical properties

can be measured and observed without changing the composition or identity of a substance

color

appearance of an object to the human eye

density

the mass of a substance per unit volume

melting point

temperature at which a solid becomes a liquid

boiling point

temperature at which a liquid becomes a gas

hardness

resistance of a material to scratching

conductivity

ability of a material to conduct heat or electricity

solubility

ability of a substance to dissolve in a solvent

mass

the amount of matter in an object

volume

the amount of space an object occupies

length

the distance between two points

shape

the external form of an object

chemical properties

describes a substance’s ability to undergo chemical reactions and form new substances

flammability

the ability of a substance to burn in the presence of oxygen

oxidation

the ability of a substance to combine with oxygen

acidity/basicity

the ability of a substance to donate or accept protons

radioactivity

the ability of an unstable atomic nucleus to spontaneously emit radiation

extensive property

property that depend on the amount of matter present

intensive property

property that do not depend on the amount of matter present

are all chemical properties intensive?

no

Intensive Chemical Properties

These properties do not depend on the quantity of the substance and remain the same regardless of how much of the substance you have. Examples include:

• Reactivity: The ability of a substance to react with other chemicals (e.g., how a substance reacts with acids or bases).

• Electronegativity: The tendency of an atom to attract electrons in a chemical bond.

• Chemical Bonding: The type of bonding (e.g., covalent, ionic) a substance can form.

• Oxidation States: The different oxidation states that an element can exhibit in various compounds.

Extensive Chemical Properties

These properties depend on the quantity of the substance and change as the amount of the substance changes. Examples include:

• Total Heat of Reaction: The total heat absorbed or released during a chemical reaction, which depends on the amount of reactants and products.

• Total Amount of Substance: The total quantity of the substance involved in a reaction.

• Volume of Gas Produced: The total volume of gas produced or consumed in a reaction, which depends on the amount of substance.

Are all physical properties extensive?

false

Intensive Physical Properties

Intensive properties do not depend on the amount of substance and remain constant regardless of how much material is present. Examples include:

• Density: The mass per unit volume of a substance (e.g., grams per cubic centimeter).

• Boiling Point: The temperature at which a substance transitions from liquid to gas (e.g., 100°C for water at standard pressure).

• Melting Point: The temperature at which a substance transitions from solid to liquid (e.g., 0°C for ice).

• Color: The color of a substance is inherent and does not change with the quantity.

• Refractive Index: The measure of how much light bends as it passes through a substance.

• Hardness: A measure of how resistant a substance is to deformation or scratching.

Extensive Physical Properties

Extensive properties depend on the quantity of the material present and change with the amount of substance. Examples include:

• Mass: The amount of matter in a sample (e.g., grams or kilograms).

• Volume: The amount of space a substance occupies (e.g., liters or cubic meters).

• Total Energy: The overall energy content of a substance, which changes with the amount of substance (e.g., thermal energy).

• Length: The measurement of how long a substance or object is.