An Overview to General Chemistry Session 1

Practice flashcards covering the classification of matter, properties of substances, chemical and physical changes, and measurement fundamentals from General Chemistry Session 1.

Chemistry

The study of matter and how we can change matter chemically and physically; the science dealing with the properties, composition, structure, and changes that matter undergoes. Also known as the “central science” or “Physical Science.”

Matter

Anything that occupies space and has mass; it is made up of “small indivisible particles” called atoms and is composed of atoms, molecules, and ions.

Solids

A state of matter with definite shape and volume, strong intermolecular forces of attraction, and vibrational molecular motion. It typically has a lattice structure.

Liquid Crystals

Also known as “PLASMA and ”MESOPHASE,“ these have intermediate properties between solids and liquids, possessing both the lattice structure of a solid and the flow properties of a liquid.

Pure Substances

Matter that has a definite or constant composition and distinct properties.

Element

The simplest form of matter that consists of one kind of atom and cannot be decomposed by simple physical or chemical means into two or more different substances.

Compound

A substance composed of two or more elements united chemically in definite proportion which cannot be changed into simpler substances under normal laboratory conditions.

Law of Definite Proportions

Also known as “Proust Law,” it states that the elemental composition of a pure compound is always the same regardless of source, with elements combined in fixed ratios of whole numbers.

Law of Multiple Proportions

States that elements can combine in different ratios of whole numbers to form different compounds; specifically applied to organic compounds.

Mixture

Composed of two or more elements or substances which are not chemically combined.

Heterogeneous mixture

A mixture containing two or more distinct phases.

Suspension

Also known as a Coarse Mixture, it is a homogeneous dispersion of finely divided solid materials that are insoluble in a liquid.

Colloids

Particles bigger than those in solutions but smaller than those in suspension; the solute particles are small and dispersed throughout the medium and exhibit light scattering.

Tyndall Effect

The light scattering effect exhibited by colloidal mixtures.

Brownian motion

The continuous zigzag movement of colloidal particles due to perfectly elastic collisions.

Homogeneous mixture

A mixture characterized by only one phase or a single phase.

Solution

A uniform mixture composed of a solute and a solvent where particle size is less than $1\,nm$.

Solute

The part of a solution that is being dissolved.

Solvent

The part of a solution that dissolves the solute.

Physical property

A property that can be measured and observed without changing the composition or identity of a substance, such as temperature, boiling point, or solubility.

Extrinsic/extensive properties

Properties that depend on the amount of matter being considered, such as weight, volume, and pressure.

Intrinsic/intensive properties

Properties that do not depend on the amount of matter being considered, such as temperature, density, and specific gravity.

Chemical property

A property that can be determined only by changing the composition or identity of a substance, such as flammability or chemical stability.

Physical Change

Changes that alter only the state or appearance of matter but not its composition.

Endothermic

A reaction where heat energy is absorbed from the environment, making the reaction cooler than surroundings; examples include melting and evaporation.

Exothermic

A reaction where heat energy is released to the environment, making the reaction hotter than surroundings; examples include freezing and condensation.

Chemical Change

Changes that alter the composition of matter wherein atoms rearrange to transform original substances into different substances.

Nuclear Change

A change in the structure, properties, or composition of the nucleus of an atom resulting in the transmutation of the element into another.

Nuclear Fission

The splitting of a heavy atom.

Nuclear Fusion

The union of two light atoms to form a bigger molecule.

Mass

The amount of matter present in a material.

Weight

Defined by the formula $\text{Weight} = \text{Mass} \times \text{pull of gravity}$.

Scientific Notation

A method used for convenience in calculation when dealing with very small or large numbers, expressed as $N \times 10^n$.