States of Matter and Atomic Structure

Vocabulary flashcards covering the particle theory of matter, phase changes, and atomic structure fundamentals from the lecture notes.

States of Matter

The three distinct physical forms that matter can take: solid, liquid, and gas.

Freezing

The change of state that occurs when a liquid turns into a solid during cooling.

Evaporation

The change of state that occurs when a liquid turns into a gas during heating.

Condensing

The change of state that occurs when a gas turns into a liquid during cooling.

Melting Point

The specific temperature at which a substance changes state from a solid to a liquid.

Element

A substance that is made up of only one type of atom.

Sub-atomic Particles

The three constituent particles that make up atoms: protons, neutrons, and electrons.

Proton

A sub-atomic particle carrying a $+1$ charge with a relative mass of $1$.

Neutron

A sub-atomic particle carrying a neutral charge ($0$) with a relative mass of $1$.

Electron

A sub-atomic particle carrying a $-1$ charge with a relative mass of approximately $0$ ($\frac{1}{1800}$).

Atomic Number

The number of protons in an atom, which also indicates the number of electrons.

Mass Number (A)

The total number of protons plus neutrons in an atom.

Calculating Neutrons

The process of determining the number of neutrons by subtracting the atomic number from the mass number ($\text{Mass Number} - \text{Atomic Number}$).