Lecture 3: Matter and Energy, Atomic Theory Flashcards

This set of vocabulary flashcards covers the fundamental concepts of matter, chemical particles, phases of matter, classification of substances, and physical vs. chemical properties and changes based on the Chem 22 lecture notes.

Atoms

The tiniest of tiniest specks of matter, represented by dots on paper.

Molecules

Bonded atoms represented as connected dots.

Mole

A measure word used to describe amounts of matter; 1 mole is equal to $6.022 \times 10^{23}$ things.

Avogadro’s Number

$6.022 \times 10^{23}$.

Solid

A phase of matter with definite shape, definite volume, small space between particles, and particle movement characterized by vibration.

Liquid

A phase of matter with indefinite shape, definite volume, small space between particles, and random particle movement.

Gas

A phase of matter with indefinite shape, indefinite volume, huge space between particles, and random particle movement.

Crystalline

Solids whose particles are organized in a repeating pattern, such as Gold or Sodium chloride.

Amorphous

Solids whose particles are disorderly.

Pure Substances

Matter made of only one type of particle; includes elements and compounds.

Mixtures

Matter made of more than one type of particle where components are not bonded together.

Element

A substance that cannot be broken down into simpler substances and contains only one type of atom.

Diatomic Seven

Seven elemental substances existing as $X_2$: $H_2$, $N_2$, $F_2$, $O_2$, $Cl_2$, $I_2$, and $Br_2$.

Compound

A substance made of two or more elements in fixed proportions that can be decomposed.

Homogeneous Mixture

A mixture where the composition is uniform throughout the substance, such as solutions of nickel (Ni) salts.

Heterogeneous Mixture

A mixture where the composition is not uniform throughout and components are often visible, such as an ice cream sundae.

Physical Property

A property of a substance that doesn’t require the substance to change identity.

Chemical Property

A property that a substance displays by changing its composition.

Chemical Change

The conversion of a substance to a new substance via a chemical reaction, changing the particle composition.

Physical Change

A change where the appearance changes but the particles remain the same, such as phase changes, shattering, or tearing.

Temperature (T)

A measure proportional to the kinetic energy or movement energy of particles.

Pressure (P)

A measure proportional to the collisions of particles.

Standard Atmospheric Pressure

$1\text{ atm}$ at sea level, which is also equal to $760.\text{ mm Hg}$ or torr.

Phase Diagram

A "map" for phase changes showing the relationship between Pressure and Temperature.

Distillation

The process of separating mixtures by exploiting differences in physical properties, such as boiling points, among components.

Filtration

A method used to separate mixtures based on differences in particle size.