Atoms, Molecules, and Bonds Vocabulary 2

Vocabulary flashcards defining key components, mixture types, and chemical bond concepts from the lecture.

Mixture

A combination of two or more components that are physically intermixed without chemical bonding between them.

Solution

A homogeneous mixture in which particles (solutes) are evenly distributed throughout the solvent.

Solvent

The substance present in the greatest amount in a solution, usually a liquid such as water.

Solute

A substance dissolved in a solvent, present in smaller amounts.

Colloid

Also known as an emulsion, a heterogeneous mixture containing large solute particles that do not settle out, giving the solution a cloudy or milky look.

Sol-gel transformation

A reversible change of a colloid from a fluid solution to a solid gel state, as seen in Jell-O and cell cytosol.

Suspension

A heterogeneous mixture containing large, visible solutes that settle out of the mixture over time if left undisturbed.

Chemical Bond

An energy relationship between the electrons of reacting atoms, rather than a physical structure.

Electron Shell

An area or energy level around an atomic nucleus occupied by electrons carrying specific amounts of kinetic and potential energy.

Valence Shell

An atom's outermost electron shell, containing the electrons with the highest potential energy that are directly involved in chemical reactions.

Octet Rule

The rule of eights stating that atoms tend to gain, lose, or share electrons to achieve 8 electrons in their valence shell for stability.

Ion

An atom that has gained or lost valence electrons, resulting in an unequal number of protons and electrons and carrying an overall electrical charge.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Ionic Bond

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

Covalent Bond

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

Nonpolar Covalent Bond

A strong covalent bond involving equal sharing of electrons between atoms, resulting in an electrically balanced molecule such as $N_2$, $CH_4$, $O_2$, or $CO_2$.

Polar Covalent Bond

A chemical bond involving unequal sharing of electrons between atoms with different electron-attracting abilities, producing an electrically polar molecule.

Electronegative Atom

An atom with a greater electron-attracting ability in a chemical bond.

Electropositive Atom

An atom with less electron-attracting ability in a chemical bond.

Dipole

A nonsymmetrical molecule, such as $H_2O$, that has two distinct charges due to unequal electron sharing.

Van der Waals Interactions

Weak interactions that enable all atoms and molecules to stick together due to asymmetric, temporary electron distribution when they are very close together.

Hydrogen Bond

A weak attractive force between an electropositive hydrogen atom of one molecule and an electronegative atom of another molecule, or within different parts of a large molecule.