Chemistry: Vocabulary Flashcards – The Molecular Nature of Matter and Change

Vocabulary flashcards covering core terms from the lecture notes on states of matter, properties, changes, energy, units, measurement, and related concepts.

States of Matter: Solid

A state with fixed shape and fixed volume; particles tightly packed and organized.

States of Matter: Liquid

A state with variable shape that conforms to the container, fixed volume; has an upper surface.

States of Matter: Gas

A state with no fixed shape or volume; particles far apart and disorganized.

Physical Property

A property observed without changing the substance’s identity; examples include color, melting point, boiling point, density.

Chemical Property

A property observed during interactions or transformation into other substances; examples include flammability and corrosiveness.

Physical Change

A change in form or state that does not alter the substance’s composition; usually reversible by changing conditions.

Chemical Change

A change that alters the composition of a substance; not reversible by simple changes in temperature.

Temperature

A measure of how hot or cold one object is relative to another.

Energy

The ability to do work.

Potential Energy

Energy due to position or configuration.

Kinetic Energy

Energy due to the motion of an object.

Total Energy

The sum of potential and kinetic energy.

Conservation of Energy

Energy is neither created nor destroyed; it can be transformed from one form to another.

SI Base Unit – Mass

Kilogram (kg).

SI Base Unit – Length

Meter (m).

SI Base Unit – Time

Second (s).

SI Base Unit – Temperature

Kelvin (K).

SI Base Unit – Amount of Substance

Mole (mol).

SI Base Unit – Electric Current

Ampere (A).

SI Base Unit – Luminous Intensity

Candela (cd).

Prefix: Kilo

10^3; symbol k; used in units like kilogram (kg).

Prefix: Centi

10^-2; symbol c; used in centimeters (cm).

Prefix: Milli

10^-3; symbol m; used in milliliters (mL).

Volume Relationships in SI

1 m^3 = 1000 dm^3; 1 dm^3 = 1000 cm^3; 1 L = 1000 mL; 1 cm^3 = 1000 mm^3; 1 mL = 1 cm^3.

Temperature Scales

Celsius, Kelvin, and Fahrenheit; differ in zero points and degree size; C and K share the same degree size.

Water Phase Points

Freezing at 0°C (273.15 K); Boiling at 100°C (373.15 K); 32°F corresponds to 0°C.

Significant Figures

Digits in a measurement including certain digits plus one uncertain digit; more sig figs = greater certainty.

Exact Numbers

Numbers with no uncertainty; defined by definition or counting (e.g., 60 min = 1 hr; 2.54 cm = 1 in).

Precision

How close a set of measurements are to each other.

Accuracy

How close measurements are to the true value.

Systematic Error

A consistent bias causing all measurements to be higher or lower than true value.

Random Error

Unpredictable fluctuations around the true value; always present.

Conversion Factor

A ratio of equivalent quantities used to express a quantity in different units.

Density

Mass per unit volume; an intensive property; density can help distinguish substances.

Density of Water

Approximately 0.998 g/cm^3 at 20°C (used as a common reference in problems).

Extensive vs Intensive Properties

Extensive: depend on amount (mass, volume); Intensive: independent of amount (density).