Basic Chemistry, Mixtures, and Chemical Bonding

Vocabulary practice flashcards covering basic chemistry concepts including mixtures, solution concentration, electron shells, types of chemical bonds, and chemical reactions.

Mixture

A substance composed of two or more components that are physically intermixed without chemical bonding.

Solution

A homogeneous mixture containing tiny solute particles that do not settle out at the bottom or scatter light.

Solvent

The component of a solution present in the greatest amount, typically a liquid such as water.

Solute

The substance dissolved in a solvent, present in smaller amounts within a solution.

Molarity ($M$)

A measure of concentration defined as the number of moles of solute per liter of solvent.

Avogadro's number

The number of molecules present in $1\text{ mole}$ of any substance, equal to $6.02 \times 10^{23}$.

Colloid

A heterogeneous mixture (also known as an emulsion) with solute particles larger than those in a solution that scatter light but do not settle out.

Sol-gel transformation

A reversible transition of a colloid from a fluid liquid state (sol) to a solid gel state (gel).

Suspension

A heterogeneous mixture containing large, visible solutes that settle out at the bottom of the container over time.

Valence shell

The outermost electron shell of an atom containing electrons with the highest potential energy, which participate in chemical reactions.

Octet rule

The principle that atoms tend to gain, lose, or share electrons to achieve $8\text{ electrons}$ in their valence shell for chemical stability.

Ionic bond

A chemical bond formed by the complete transfer of valence shell electrons from one atom to another, resulting in attraction between oppositely charged ions.

Anion

An ion carrying a net negative charge formed when an atom gains one or more electrons.

Cation

An ion carrying a net positive charge formed when an atom loses one or more electrons.

Covalent bond

A chemical bond formed when two atoms share two or more valence shell electrons.

Polar covalent bond

A covalent bond formed by the unequal sharing of electrons between atoms with differing electron-attracting abilities, resulting in partial charges.

Electronegative atom

An atom with a strong electron-attracting ability that exerts a greater pull on shared electrons in a chemical bond.

Electropositive atom

An atom with a weaker electron-attracting ability in a chemical bond, resulting in a lesser pull on shared electrons.

Hydrogen bond

A weak attraction between an electropositive hydrogen atom of one molecule and an electronegative atom of another molecule.

Reactants

The starting substances that enter together into a chemical reaction.

Product

The resulting chemical substance produced by a chemical reaction.

Synthesis reaction

A chemical reaction in which atoms or simple molecules combine to form a larger, more complex molecule.

Decomposition reaction

A chemical reaction in which a molecule is broken down into smaller molecules or constituent atoms.

Exchange reaction

A reaction involving both synthesis and decomposition, where chemical bonds are both formed and broken.

Redox reaction

A reduction-oxidation exchange reaction in which electrons are transferred, causing one substance to be oxidized and another to be reduced.

Exergonic reaction

A chemical reaction that results in a net release of energy, yielding products with lower potential energy than the reactants.

Endergonic reaction

A chemical reaction that results in a net absorption of energy, yielding products with higher potential energy than the reactants.

Chemical equilibrium

A state in a reversible chemical reaction where neither the forward nor the reverse reaction rate is dominant.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing permanent chemical change or becoming part of the product.

Enzyme

A biological catalyst that accelerates chemical reactions by lowering the required activation energy.