Chapter 1: Matter, Measurements, and Problem Solving - Vocabulary Flashcards

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

Atom

The submicroscopic particle that is the fundamental building block of ordinary matter; free atoms are rare in nature.

Molecule

A group of two or more atoms bonded together; the smallest unit of a compound that retains its properties.

Water molecule

A molecule consisting of two hydrogen atoms and one oxygen atom (H2O).

Hydrogen peroxide

A molecule with formula H2O2; an example of a different molecule formed by changing the number of oxygen atoms.

Central goal of chemistry

To understand the substances around us by studying the atoms and molecules that compose them.

Chemistry

The science that studies the behavior of matter by examining atoms and molecules.

Empirical

Based on observation and experiment rather than theory alone; data-driven.

Scientific method

A process for understanding nature via observation, hypothesis, experimentation, and formulation of laws and theories.

Observation

Descriptions about the characteristics or behavior of nature; data collected from the physical world.

Hypothesis

A tentative interpretation of observations that is testable and falsifiable.

Falsifiable

Capable of being tested and potentially proven false.

Scientific law

A concise statement that summarizes past observations and predicts future ones.

Theory

A model for how nature is and why; explains underlying reasons for observations and laws; validated by experiments.

Dalton's atomic theory

An early theory describing atoms as the basic building blocks and how they combine to form substances.

Matter

Anything that occupies space and has mass.

States of matter

Solid, liquid, or gas; matter changes state with temperature.

Solid

A state with fixed volume and rigid shape; particles vibrate in place.

Crystalline solid

A solid with a highly ordered, repeating arrangement of atoms (long-range order).

Amorphous solid

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

Liquid

A state with fixed volume but shape that conforms to its container and flows.

Gas

A state with substantial empty space between particles and high compressibility.

Density

Mass per unit volume; an intensive property that can vary with temperature.

Intensive property

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

Extensive property

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

Pure substance

Matter composed of a single component with invariant composition.

Element

A substance that cannot be chemically broken down into simpler substances; consists of one type of atom.

Compound

A substance composed of two or more elements in fixed definite proportions.

Mixture

A substance made of two or more components in varying proportions.

Heterogeneous mixture

Mixture in which the composition varies by region and components are visible.

Homogeneous mixture

Mixture that appears uniform throughout; components are not easily distinguished.

Physical change

A change that alters state or appearance but not the substance’s composition.

Chemical change

A change that alters composition and forms new substances.

Physical property

A characteristic observed without changing the substance's composition.

Chemical property

A characteristic observed only by changing the substance's composition via a chemical reaction.

Volume

A measure of space occupied; SI unit is cubic meters (m^3); often measured in liters.

Mass

Quantity of matter; SI unit is the kilogram; mass is not weight.

Derived unit

A unit formed by combining base units (e.g., volume m^3, density kg/m^3).

SI base units

The seven fundamental units that define all others: meter, kilogram, second, kelvin, mole, ampere, candela.

Meter

SI base unit of length; defined by the distance light travels in vacuum in a defined time.

Kilogram

SI base unit of mass; 1 kg ≈ 2.205 pounds.

Second

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

Kelvin

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

Mole

SI base unit of amount of substance; amount of entities in a system.

Prefix multipliers

Prefixes that scale units by powers of ten (e.g., kilo 10^3, milli 10^-3, micro 10^-6, nano 10^-9).

Displacement

A method to determine the volume of an irregular object by measuring the volume of water it displaces.