Chemistry: Matter, States, Changes, and Gas Laws

Vocabulary flashcards covering the properties and states of matter, phase changes, chemical and physical properties/changes, and fundamental gas laws.

matter

Anything that has massa takes up space.

pure substances

When every piece of the matter is exactly the same.

mixtures

With more than one type of substance mixed together.

elements

A pure substance because every atom of the sample is the same element.

compounds

Formed when more than one element combines with chemical bond.

homogeneous mixtures

Present when a mixture looks the same throughout.

heterogeneous mixture

Clearly shows more than one component-it can have layers, chunks, floating items, bubbles, or some other indication that there is more than one substance present.

solid

Closely packed together, and although they don't appear to be moving, they are vibrating in place.

liquid

Have more energy, are farther apart, and are free to flow around each other.

Gas

Atoms or molecules have even higher energy, are spaced as far apart as their container will allow, and move randomly and rapidly throughout the entire container.

melting

Becomes a liquid.

freezing

Turns back into a solid.

boiling

A liquid can turn into a gas.

condensing

A gas can become a liquid.

sublimation

When a solid undergoes a change directly to a gas.

deposition

The opposite process, from gas directly to solid.

melting/freezing point

The temperature at which a solid melts or a liquid freezes is the same.

boiling/condensation point

A liquid can turn into a gas when it is boiled, and a gas can become a liquid by condensing. These two processes happen at the same temperature as well.

kinetic energy

The energy of motion.

physical properties

Those that you can observe without changing the atoms or molecules that make up the matter.

chemical properties

Describe how something reacts with other elements or molecules.

physical change

Those which do not affect the chemical structure of the molecules or elements.

chemical change

Those that change how the elements or molecules are chemically arranged.

pressure

The force of the gas atoms or molecules running into the wall of their container.

atmospheric pressure

The result of layers of air molecules above us in the atmosphere causing pressure.

kinetic-molecular theory

The theory that helps explain these behaviors of gases.

real gas

Gases that sometimes behave slightly differently than kinetic-molecular theory assumes.

diffusion

The speed with which gas particles move across a space.

effusion

The speed with which gas particles escape through a tiny hole in the container.

Avogadro's Law

The volume ($V$) of an ideal gas is directly proportional to the number of moles ($n$) of the gas, provided the temperature and pressure are held constant.

Charles' Law

The volume ($V$) of a fixed amount of gas is directly proportional to its absolute temperature ($T$) in Kelvin, provided the pressure is held constant.

Boyle's Law

The volume ($V$) of a fixed amount of gas is inversely proportional to its pressure ($P$), provided the temperature is held constant. As pressure increases, volume decreases.

Combined Gas Law

Combines Boyle's Law, Charles's Law, and Gay-Lussac's Law to examine the relationship between pressure, volume, and temperature for a fixed amount of gas (constant moles).

Ideal Gas Law

A single equation of state that models the relationship between all four gas variables: pressure ($P$), volume ($V$), number of moles ($n$), and absolute temperature ($T$).

STP

A standard set of conditions established to enable convenient comparisons between different sets of gas data.