Properties, Changes, and States of Matter: Physics and Chemistry

What are properties of matter?

Characteristics and behaviors used to describe matter.

What are the two main types of properties?

Physical and Chemical.

What is a physical property?

A property that can be observed or measured without changing the identity of the substance.

What is a chemical property?

A property that becomes evident during a chemical reaction and changes the substance.

What are examples of physical properties?

Mass, density, volume, boiling point, melting point, conductivity, heat capacity, malleability, ductility, solubility, luster, color.

What is mass?

The amount of matter in a substance; measured in kilograms (kg).

What is the formula for mass?

M = F / a (force ÷ acceleration).

What is density?

Mass divided by volume; varies with temperature and pressure.

What is volume?

The amount of space an object occupies.

What is boiling point?

Temperature at which a liquid changes to gas.

What is melting point?

Temperature at which a solid changes to liquid.

What is conductivity?

Ability of a substance to allow electricity to flow.

What is heat capacity?

Amount of heat needed to raise temperature of a mass by 1 K (J/K).

What is malleability?

Ability to be hammered or pressed into thin sheets.

What is ductility?

Ability to be drawn into wires.

What are extensive properties?

Depend on the amount of matter (mass, volume).

What are intensive properties?

Independent of the amount of matter (color, density, boiling point).

What are examples of physical changes?

Freezing water, crushing a can, sanding wood, bending a paper clip, cutting hair, mixing oil and vinegar.

What are examples of chemical properties?

Reactivity, flammability, toxicity, oxidation states, heat of combustion, chemical stability.

What are examples of chemical changes?

Milk souring, rusting iron, burning wood, vinegar + baking soda reaction, Statue of Liberty turning green.

What are signs of chemical change?

Change in temperature, production of odor, change in color, formation of bubbles, formation of a solid/precipitate.

What is an exothermic reaction?

Energy released.

Changing states of matter

The physical property of substances that enables solids, liquids and gases can change their states under certain conditions.

Mass

The physical property of substances that is the resistance of an object to movement when a force is applied and it is expressed in terms of kilograms (kg).

Density

The physical property of substances that is the measurement of mass in respect to and in a relationship with volume.

Volume

The physical property of substances that is the measurement of the quantity or amount of matter in a three-dimensional space.

Boiling point

The physical property of substances that is the point at which a liquid changes into a vapor.

Melting point

The physical property of substances that is the temperature at which a solid transforms and changes into a liquid.

Conductivity

The physical property of substances that is the measure of a substance's ability, or lack of ability, to conduct electricity.

Heat capacity

The physical property of substances that is the amount of heat that must be added or taken away from a substance to achieve a certain temperature.

Malleability

The physical property of substances that is the degree of a solid's ability to change its shape and form under stress.

Tensile stress

The stress that is applied to the solid in respect to its malleability.

What is energy?

The ability to do work or cause change.

What is kinetic energy?

The energy of motion.

How do particles behave with high kinetic energy?

They move fast and far apart.

How do particles behave with low kinetic energy?

They move slow and close together.

What is thermal energy?

The total kinetic energy of all particles in a sample of matter.

What is temperature?

The average kinetic energy of particles in a substance.

What is heat?

The transfer of thermal energy from a hotter substance to a cooler one.

What are the three main states of matter?

Solid, liquid, and gas.

What are the properties of solids?

Definite shape and volume; particles close together, vibrate in place.

What are the properties of liquids?

Definite volume, no definite shape; particles further apart, slide past each other.

What are the properties of gases?

No definite shape or volume; particles move very fast with most kinetic energy.

What is a change of state?

A change from one physical state to another due to energy transfer.

What is melting?

Solid → liquid; absorbs thermal energy.

What is freezing?

Liquid → solid; releases thermal energy.

What is boiling/vaporization?

Liquid → gas at boiling point; absorbs energy.

What is evaporation?

Liquid → gas below boiling point; absorbs energy.

What is condensation?

Gas → liquid; releases energy.

What is sublimation?

Solid → gas directly; absorbs energy.

What is deposition?

Gas → solid directly; releases energy.

What is a chemical reaction?

Transformation of one or more substances into different substances.

How are chemical reactions different from state changes?

Chemical reactions create new substances; state changes keep the same substance in a different form.

What are the five main types of chemical reactions?

Synthesis, decomposition, single replacement, double replacement, combustion.

What is an endothermic reaction?

A chemical reaction that absorbs heat/energy.

What is an exothermic reaction?

A chemical reaction that releases heat/energy.

What causes chemical reactions?

Interactions of electrons — breaking and forming chemical bonds.

What factors affect reaction rates?

Type of reagents, concentrations, temperature, and pressure.

How does temperature affect reaction rate?

Higher temperature speeds reactions by weakening bonds and increasing collisions.