Chemistry Study Guide: Matter, Mixtures, History, and the Scientific Method

A comprehensive vocabulary flashcard set covering fundamental chemistry concepts, properties of matter, mixture separation methods, key historical figures in atomic theory and chemistry, and the core components of the scientific method.

Matter

Anything that has mass and occupies space.

States of Matter

The three most common forms in which matter exists: solid, liquid, and gas.

Intensive Property

A property that does not depend on the amount of matter present, such as density or temperature.

Extensive Property

A property that depends directly on the amount of matter present, such as mass and volume.

Physical Property

A characteristic of matter that can be observed or measured without changing the chemical composition of the substance, such as density, boiling point, color, mass, volume, or solubility.

Chemical Property

A characteristic that describes the ability of a substance to transform into another substance, such as flammability and tendency to oxidize.

Balance

An instrument used to measure the mass of an object or substance.

Thermometer

An instrument used to measure temperature.

Graduated Cylinder

A laboratory instrument used to measure the volume of a liquid.

Density

The ratio between the mass of a substance and the volume it occupies, calculated using the formula $\text{density} = \frac{\text{mass}}{\text{volume}}$ ($d = \frac{m}{V}$).

Mixture

The physical combination of two or more substances that each retain their individual properties.

Homogeneous Mixture

A mixture with a uniform composition throughout whose components cannot be easily distinguished, such as air or salt completely dissolved in water.

Heterogeneous Mixture

A mixture with a non-uniform composition in which individual components or phases can be distinguished, such as oil and water or a salad.

Pure Substance

Matter that has a definite and fixed chemical composition, unlike a mixture which is physically combined.

Filtration

A separation method used to separate an insoluble solid from a liquid, such as separating sand from water.

Decantation

A separation method based on differences in density, allowing layers to settle or a solid to sediment before pouring off one part.

Magnetic Separation

A method used to separate magnetic materials, such as iron filings, from non-magnetic substances using a magnet.

Evaporation / Crystallization

A separation technique used to recover a dissolved solid (such as salt) from a liquid solution.

Distillation

A separation method that involves heating a liquid mixture to vaporize a component and condensing the vapor, utilizing differences in boiling points.

Chromatography

A technique used to separate the individual components of a mixture based on how they travel across a material.

Sieving

A mechanical separation method used to separate solid particles of different sizes using a mesh or screen.

John Dalton

Scientist who proposed a modern atomic theory in the early 19th century.

J. J. Thomson

Scientist who discovered the electron and proposed the plum pudding atomic model.

Ernest Rutherford

Scientist who proposed that an atom has a small, dense, positively charged nucleus and that most of the atom is empty space.

Niels Bohr

Scientist who proposed that electrons occupy defined orbits or energy levels around the nucleus.

Antoine Lavoisier

Scientist who helped establish modern chemistry and formulated the law of conservation of mass.

Law of Conservation of Mass

Principle stating that in a chemical reaction within a closed system, total mass is conserved: the mass of the reactants is equal to the mass of the products.

Dmitri Mendeléyev

Scientist who organized the chemical elements into a periodic table and identified recurring patterns in their properties.

Marie Curie

Scientist who conducted fundamental investigations on radioactivity and contributed to the understanding of radioactive elements.

Scientific Milestone

A significant discovery, idea, or advancement that fundamentally transforms or advances the progress of science.

Scientific Method

An orderly procedure used to investigate questions, gather evidence, and build well-founded explanations.

Observation and Problem Formulation

The standard first step of the scientific method, which involves observing a phenomenon and identifying or posing a specific question or problem.

Hypothesis

A provisional explanation or answer to a scientific question that can be tested through investigation.

Experimentation

Organized and controlled procedures used to test the validity of a hypothesis.

Data Analysis

The process of organizing, examining, and interpreting experimental data prior to formulating a conclusion.

Variable

Any factor in an investigation that can change, be measured, or be controlled.

Independent Variable

The factor that is deliberately altered or manipulated by the researcher in an experiment.

Dependent Variable

The factor that is measured in an experiment to observe the effects caused by changes in the independent variable.

Controlled Variable

A factor held constant in an experiment to ensure that results are primarily due to the specific variable under investigation.

Scientific Knowledge

Knowledge that is grounded in observations and empirical evidence, which can be verified and revised when presented with new evidence.