Heat and Temperature: An Overview

Flashcards covering key vocabulary related to heat, temperature, and phases of matter from the lecture.

Matter

The material that makes up solids, liquids, and gases.

Atoms

The smallest unit of matter.

Molecules

Units made up of more than one atom bonded together (e.g., N2, O2, CO2).

Cohesive Forces

Interactions within a substance where it would rather interact with itself and stick together than with its container (e.g., oil in a glass tube).

Adhesive Forces

Interactions where a substance wants to interact with the material it is in contact with, bonding unlike things together (e.g., water in a glass tube).

Meniscus

The curve observed in the surface of a liquid in a narrow glassware, demonstrating adhesive forces between the liquid and the glass.

Solids

A phase of matter characterized by a fixed shape and fixed volume, held together by strong cohesive forces in an organized structure (like a crystal lattice).

Liquids

A phase of matter with a variable shape but a fixed volume, where molecules can slip past each other but cannot escape their cohesive forces.

Gases

A phase of matter with both variable shape and variable volume, where molecules have enough kinetic energy to freely escape each other's cohesive forces.

Temperature

A measure of the average kinetic energy of the molecules of a substance.

Kinetic Energy

The energy of a moving object; in the context of temperature, it refers to the energy of moving atoms and molecules.

Thermal Equilibrium

The state where heat transfers from a hotter object to a colder object until both reach the same temperature, resulting in no net heat transfer.

Kinetic Theory of Gases

A theory that describes gases as being made up of tiny, fast-moving particles (atoms or molecules) undergoing elastic collisions, where temperature is a measure of their average kinetic energy.

Elastic Collisions

Collisions between molecules or atoms where energy is transferred but not lost, allowing for continuous motion.

Melting Point

The specific temperature at which a substance transitions from a solid to a liquid phase.

Boiling Point

The specific temperature at which a substance transitions from a liquid to a gas phase.

Expansion (Thermal)

The slight increase in volume or length of a material (solid, liquid, or gas) when its temperature increases.