Chapter 1: Science and Measurement

A comprehensive set of flashcards covering key vocabulary from the lecture notes on Science and Measurement.

Scientific Method

A structured process to understand the natural world.

Hypothesis

A proposed explanation based on reason and evidence, not a guess.

Scientific Theory

A thoroughly tested explanation widely accepted for observed facts.

Scientific Law

Summarizes observations but does not explain why something occurs.

Scientific Notation

A method to express very large or small numbers in a compact form.

Significant Figures

The precision of a measurement based on the measurement with the fewest significant figures.

Accuracy vs Measurement

Accuracy is how close a measured value is to the true value; a measurement is a number that represents a physical quantity.

International System of Units (SI)

The modern form of the metric system used globally in science.

Density

A measure of mass relative to the volume of an object.

Matter

Anything that has mass and takes up space.

Pure Substances

Substances with definite compositions, like elements and compounds.

Mixtures

Physical combinations of two or more pure substances.

Homogeneous Mixture

A mixture with a uniform composition, often called a solution.

Heterogeneous Mixture

A mixture that does not have a uniform composition.

States of Matter

The distinct forms that matter takes on, including solid, liquid, and gas.

Physical Properties

Characteristics that can be observed without changing composition.

Chemical Properties

Characteristics that describe how a substance can chemically react.

Physical Change

A change in physical properties without a change in chemical composition.

Chemical Change

A change that alters the composition of a substance.

Energy

The capacity to do work or transfer heat.

Kinetic Energy

Energy associated with motion.

Potential Energy

Stored energy based on position or arrangement.

Temperature

Measures the average kinetic energy of particles in a substance.

Specific Heat

The amount of heat needed to raise the temperature of one gram of a substance by one Celsius degree.

Endothermic Process

Any process that absorbs heat energy.

Exothermic Process

Any process that releases heat energy.

Heating Curve

A graph showing the temperature of a substance as heat is added.

Elements

Substances composed of only one type of atom.

Periodic Table

An organized table of elements by increasing atomic number.

Subatomic Particles

Particles within an atom, including protons, neutrons, and electrons.

Isotopes

Atoms of an element with the same number of protons but different numbers of neutrons.

Mass Number

The sum of protons and neutrons in an atom.

Atomic Mass

Weighted average of the masses of all naturally occurring isotopes of an element.

Radioactivity

The emission of particles or energy from unstable nuclei to gain stability.

Half Life

The time required for half of the atoms in a sample to decay.