General Chemistry I - Chapter 1: Matter, Measurement, and Problem Solving

Vocabulary flashcards covering key terms from Chapter 1: Matter, Measurement, and Problem Solving.

Matter

Anything that occupies space and has mass.

States of matter

The physical forms of matter: solid, liquid, and gas, which differ in particle arrangement and movement; state changes with temperature.

Atoms

Submicroscopic particles that are the fundamental building blocks of ordinary matter; form molecules when bound together.

Molecules

Two or more atoms bound together; the smallest unit of a compound.

Water molecule

H2O: two hydrogen atoms and one oxygen atom held together by a chemical bond.

Central goal of chemistry

To understand the behavior of matter by studying the atoms and molecules that compose it.

Graphite vs diamond

Both are carbon; graphite has sheet-like structures, while diamond has a three-dimensional rigid network.

Liquid water

Water composed of H2O molecules; liquid state with fixed volume but shape that adapts to its container.

Elements

Pure substances that cannot be chemically broken down into simpler substances; composed of one type of atom.

Compounds

Pure substances composed of two or more elements in fixed definite proportions.

Pure substance

Matter with invariant composition; either an element or a compound.

Mixtures

Substances composed of two or more components in varying proportions.

Heterogeneous mixture

Mixture with non-uniform composition; components are visibly different (e.g., salt and sand).

Homogeneous mixture

Mixture with uniform composition; appears as a single substance (e.g., sugar solution).

Distillation

Separation of mixtures by boiling the more volatile component and condensing it.

Filtration

Separation of an insoluble solid from a liquid by passing the mixture through filter paper.

Physical change

Change that alters state or appearance but not the chemical composition.

Chemical change

Change that alters the composition, forming new substances.

Physical property

Property observed without changing composition (odor, color, density, melting/boiling point).

Chemical property

Property observed through chemical change (flammability, acidity, toxicity).

Energy

The capacity to do work; includes forms such as kinetic, potential, thermal, electrical, and chemical energy.

Forms of energy

Potential, kinetic, thermal, electrical, and chemical energy.

Law of conservation of mass

Matter is neither created nor destroyed in a chemical reaction; mass is conserved.

Scientific law

A brief statement that summarizes many observations and can predict future ones; not violable like civil laws.

Scientific theory

A well-supported model explaining underlying causes of observations and laws; validated by experiments and not proven absolutely.

Hypothesis

A tentative explanation or educated guess that can be tested by experiments.

Observations

Measurements or notes about nature that guide scientific thinking.

Experiment

A controlled procedure to test a hypothesis.

SI base units

The fundamental units of the International System: meter (length), kilogram (mass), second (time), kelvin (temperature), mole (amount of substance), ampere (electric current), candela (luminous intensity).

Meter

SI base unit of length; defined as the distance light travels in vacuum in 1/299,792,458 seconds.

Kilogram

SI base unit of mass; 1 kg = 2.205 pounds; gram is 1/1000 of a kilogram.

Second

SI base unit of time; defined by a cesium-133 atomic transition.

Kelvin

SI base unit of temperature; absolute scale with 0 K as absolute zero.

Temperature scales

Kelvin (absolute), Celsius, and Fahrenheit; conversions exist between them.

Absolute zero

0 K; the lowest possible temperature where molecular motion virtually stops.

Volume

Space that a substance occupies; derived unit in cubic meters (m^3) or liters (L).

Density

Mass per unit volume (m/v); an intensive property with units such as g/cm^3.

Intensive property

Property that does not depend on the amount of substance (e.g., density).

Extensive property

Property that depends on the amount of substance (e.g., mass).

Derived units

Units formed from base units, such as volume (m^3 or L) and density (g/cm^3 or kg/m^3).

Dimensional analysis

A problem-solving method using unit conversions to ensure correct units in calculations.

Unit conversion

Expressing a quantity in terms of different units using conversion factors.

SI prefixes

Multipliers that scale units by powers of ten (e.g., kilo = 10^3, mega = 10^6, milli = 10^-3).

Significant figures

Digits in a measurement that carry meaningful precision; rules govern counting and rounding.

Accuracy

How close a measurement is to the true value.

Precision

How close a series of measurements are to each other.

Crystalline solid

A solid with long-range, repeating order (e.g., table salt, diamond).

Amorphous solid

A solid lacking long-range order (e.g., glass, plastic).

Boiling point

Temperature at which a liquid rapidly becomes vapor; related to vapor pressure.

Molar mass and density units

Density commonly expressed in g/cm^3; molar mass in g/mol (contextual to chemistry).