Properties and Classification of Matter & Atomic Structure Flashcards

Vocabulary flashcards generated from lecture notes covering matter classifications, chemical and physical properties/changes, atomic history, subatomic particles, and isotope terminology.

Chemistry

The study of matter and the changes it undergoes.

Matter

Anything that has volume (takes up space), mass, and undergoes changes.

Kinetic Energy

Energy associated with motion.

Potential Energy

Stored energy.

Atom

The smallest particle of an element that still has the properties of that element.

Element

A pure substance made up of only one kind of atom, having a unique set of properties and a unique chemical symbol shown on the periodic table.

Pure Substance

Matter that contains only one type of particle and can exist as a solid, liquid, or gas.

Mixture

Matter that contains two or more different types of particles and can be any combination of solid, liquid, or gas.

Compound

A pure substance made of two or more different elements chemically combined where each particle has the same proportion of elements.

Homogeneous Mixture

A solution where particles of different substances are so evenly spread that it appears to be one substance and components cannot be visually separated.

Heterogeneous Mixture

A mechanical mixture where particles of different substances remain in clumps and components can be visually determined.

Physical Properties

Characteristics that describe the look or feel of a substance, such as mass, volume, color, texture, and pH.

Physical Changes

Occurrences where a substance changes a physical property but not its chemical composition, resulting in no new substances being formed.

Chemical Properties

Characteristics that describe the ability of a substance to change into a different substance, such as flammability, combustibility, and tendency to oxidize.

Chemical Changes

Occurrences that rearrange the bonds in a substance to form a new substance.

Intensive Physical Properties

Physical properties that do not depend on the amount of substance present, such as color, boiling point, and melting point.

Extensive Physical Properties

Physical properties that depend on the amount of substance present, such as mass and volume.

Law of Conservation of Matter

The law stating that in a chemical reaction, matter, mass, and atoms are neither created nor destroyed.

Law of Definite Proportions

Proust's law stating that a compound is always composed of a fixed or identical proportion of elements by mass.

Law of Multiple Proportions

Dalton's law stating that the ratio of the masses of elements in a compound is always a small, whole number.

Billiard Ball Model

Dalton's 1803 model proposing that atoms were solid sphere balls and the smallest whole particle in everything.

Planetary Model

Bohr's 1922 model proposing that the atom has a positive nucleus at the center with negative particles orbiting it.

Quantum Mechanical Model

The modern atomic model developed by Schrödinger using his wave equation.

Uncertainty Principle

Heisenberg's principle stating that the speeds and positions of electrons are uncertain.

Proton

A positively charged subatomic particle located in the nucleus with a mass of $1\,\text{AMU}$ that is unique to each element and determines its atomic number.

Neutron

A neutral subatomic particle located in the nucleus with a mass of $1\,\text{AMU}$ that contributes to atomic mass.

Electron

A negatively charged subatomic particle located outside the nucleus in the electron cloud with a mass of $1/1836\,\text{AMU}$ that allows atoms to bond and determines charge.

Nucleus

The center of the atom containing protons and neutrons, which accounts for all of the atom's mass.

Electron Cloud

The region outside the nucleus containing negatively charged electrons, which accounts for all of the atom's volume.

Quarks

Smaller particles discovered by Gell-Mann that make up protons and neutrons, with $3$ quarks per proton or neutron.

Atomic Number

The number of protons in the nucleus of an element, represented by symbol $Z$, which determines the order of elements on the periodic table.

Atomic Mass

The sum or weighted average mass of all the isotopes of a particular element, as indicated on the periodic table.

Mass Number

The total sum of protons and neutrons in an atom's nucleus, represented by symbol $A$.

Isotope

An atom that has the same number of protons (atomic number) but a different number of neutrons relative to other atoms of the same element.

Net Charge

The overall charge of an atom based on the ratio of protons to electrons ($\text{p}^+ : \text{e}^-$).

Ion

An atom that has gained or lost electrons, resulting in a net non-zero charge.

Nuclear Charge

The positive charge of an atom based strictly on the number of protons in its nucleus, which remains constant for a given element.