SAAT Preparation Course: Chemistry - Chapter 2 Flashcards

Vocabulary flashcards for Chapter 2 of the SAAT Chemistry Preparation Course, covering matter, properties, and changes.

Matter

Anything that has mass and occupies space.

Solid

Constant shape and volume, high density, atoms vibrate in fixed positions.

Liquid

Fixed volume, adopts the shape of the container, less dense than solids (except water).

Gas

No fixed volume, takes the shape of the container, very low density, highly compressible.

Plasma

Ionized gas made of free electrons and ions, found in stars and lightning.

Melting

When a solid changes into a liquid, occurs at the melting point.

Freezing

When a liquid changes into a solid, occurs at the freezing point (same as melting point).

Evaporation

When a liquid changes into a gas, occurs at the surface of the liquid.

Condensation

When a gas changes into a liquid on cooling.

Sublimation

When a solid changes directly into a gas without becoming a liquid.

Deposition

When a gas changes directly into a solid without becoming a liquid.

Evaporation

Occurs at the surface of a liquid, at any temperature below boiling point, cools the liquid.

Boiling

Occurs throughout the liquid, at a specific boiling point, forms bubbles of vapor.

Triple Point

The temperature and pressure where a substance's solid, liquid, and gas phases exist in equilibrium.

Critical Point

The temperature and pressure above which a liquid cannot exist; the substance becomes a supercritical fluid.

Physical Change

A change in a substance without changing its chemical composition.

Chemical Change

A change in which one or more new substances are formed; involves a chemical reaction.

Intensive Property

A property that does not depend on the amount of matter (e.g., luster, boiling point).

Extensive Property

A property that depends on the amount of matter (e.g., size, mass, volume).

Pure Substance

Matter with a uniform and constant composition.

Element

A pure substance that cannot be separated into simpler substances by physical or chemical means.

Compound

Made up of two or more elements combined chemically.

Law of Constant Proportions

A chemical compound always has its elements in a fixed ratio by mass.

Law of Multiple Proportions

When elements combine to form different compounds, the ratios of the masses of the second element that combine with a fixed mass of the first element will be in ratios of small whole numbers.

Mixture

Combination of two or more pure substances in which each retains its individual chemical properties.

Homogenous Mixture (Solution)

A mixture where the composition is constant throughout (evenly mixed).

Heterogeneous Mixture

A mixture where the individual substances remain distinct.

Alloy

Solid-solid solution known as steel.

Suspension

Mixture containing particles that settle out if left undisturbed.

Colloid

Heterogeneous mixture with particle sizes between 1nm and 1000nm in diameter that does not settle out.

Tyndall Effect

Scattering of light due to dispersed colloid particles.

Brownian Motion

Random movement of liquid colloid particles caused by collisions with molecules of the dispersion medium.

Filtration

Technique using a porous barrier to separate a solid from a liquid in a heterogeneous mixture.

Distillation

Separation technique based on differences in boiling points of substances.

Crystallization

Separation technique for homogenous mixtures that results in the formation of pure solid particles.

Sublimation

Process of a solid changing directly to a gas.

Chromatography

Technique that separates components of a mixture based on their tendency to travel across the surface of another material.

Energy

The capacity to do work or produce heat.

Heat

Energy that is transferred from one object to another because of a temperature difference.

Specific Heat Capacity

The amount of energy required to raise the temperature of one gram of a substance by one degree Celsius.

Phase Transition

A change in the state of a substance that does not involve a change in its chemical composition.

Latent Heat

The heat absorbed or released during a phase change.

Temperature

A measure of the average kinetic energy of the particles in a sample of matter.

Conduction

Heat transfer by direct contact.

Convection

Heat transfer by the movement of fluids.

Radiation

Heat transfer by electromagnetic waves.

Conductor

A material that easily conducts heat.

Insulator

A material that does not easily conduct heat.