Introduction to Chemistry: Scientific Method, Matter, and Units

Vocabulary flashcards covering the scientific method, classifications and states of matter, physical and chemical properties and changes, property types, standard SI units, and scientific notation based scientific notation rules.

Scientific Method

A logical and systematic approach to solving problems by making observations, forming hypotheses, and testing ideas.

Observation

The initial step in the scientific method where a problem or question is identified.

Hypothesis

A proposed possible explanation for an observed problem or question that can be tested.

Experiment

The step in the scientific method where a hypothesis is tested through controlled studies.

Data Collection

The step in the scientific method where experimental results are recorded and analyzed.

Conclusion

The step in the scientific method where a hypothesis is accepted, rejected, or revised based on experimental data.

Communication

The final step in the scientific method where findings are shared with others.

Matter

Anything that has mass and takes up space.

Gas

A state of matter with particles that are far apart from each other, having no definite shape and no definite volume.

Liquid

A state of matter with particles closer together, having a definite volume but no definite shape.

Solid

The most condensed form of matter, having particles tightly packed next to each other, giving both a definite shape and a definite volume.

Pure Substance

A classification of matter that has a fixed, definite composition, consisting of either elements or compounds.

Element

A pure substance made of just one type of atom, such as pure aluminum.

Compound

A pure substance composed of two or more elements chemically combined in a fixed ratio, such as water ($H_2O$).

Mixture

A combination of two or more substances that are physically blended but not chemically bonded.

Homogeneous Mixture

A mixture that has the same composition throughout and looks uniform, such as brass.

Heterogeneous Mixture

A mixture that does not have a uniform composition, where the different parts are visible.

Physical Property

A characteristic of a substance that can be observed or measured without changing the substance's chemical identity.

Chemical Property

A characteristic describing a substance's ability or potential behavior to change into a completely new substance through a chemical reaction.

Physical Change

A process that alters the appearance or state of a substance without changing its chemical identity or composition.

Chemical Change

A process, also called a chemical reaction, that converts one or more substances into new substances by rearranging, adding, removing, or replacing atoms.

Intensive Property

A property of matter that is independent of the amount of substance present, such as color or melting point.

Extensive Property

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

SI Base Units

The seven fundamental units of the metric system: kilogram for mass, meter for length, Kelvin for temperature, mole for amount of substance, second for time, ampere for electric current, and candela for luminous intensity.

Derived Units

Scientific units built from combinations of the seven SI base units, such as meters per second ($\text{m/s}$) for speed or cubic meters ($\text{m}^3$) for volume.

Scientific Notation

A standard format for expressing very large or very small numbers in the two-part form $y \times 10^x$.

Coefficient (Scientific Notation)

The significant digit part ($y$) in scientific notation, which must be a number greater than or equal to $1$ and less than $10$.

Exponent (Scientific Notation)

The power of $10$ ($x$) in scientific notation that indicates how many places to move the decimal point, where a positive value indicates a large number and a negative value indicates a small number.