Chapter2 Study Guide: Chemical Level of Organization

Vocabulary flashcards generated from lecture notes on Chapter 2, covering atomic structure, elements, bonds, mixtures, and pH.

Matter

Anything that occupies space and has mass.

Chemistry

The study of matter and its interactions.

Element

A basic substance composed of one type of atom.

Major Elements of the Human Body

The $4$ major elements—Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N) (memory cue: O-C-H-N)—that make up about $96\%$ of total body mass.

Minor Elements

The $7$ elements that account for about $4\%$ of body mass in the human body.

Trace Elements

The $13$ elements present in very small amounts in the human body.

Proton

A subatomic particle with a positive charge located in the nucleus.

Neutron

A subatomic particle with no charge located in the nucleus.

Electron

A subatomic particle with a negative charge located in the electron cloud around the nucleus.

Atomic Number

The number of protons in an atom.

Mass Number

The total number of protons plus neutrons in an atom.

Isotopes

Atoms of the same element with the same number of protons but different numbers of neutrons, resulting in different masses.

Radioisotopes

Unstable isotopes that undergo radioactive decay and release radiation.

Ion

A charged particle formed through the gain or loss of electrons.

Ionization

The gain or loss/transfer of electrons that produces charged particles.

Anion

A negatively charged ion formed when an atom gains electrons (memory cue: ANION = A Negative ION).

Cation

A positively charged ion formed when an atom loses electrons.

Ionic Bond

A chemical bond formed by the attraction between a cation and an anion, involving the transfer of electrons.

Salt

A neutral compound made from ions.

Covalent Bond

A strong chemical bond formed when atoms share electrons.

Polar Covalent Bond

A covalent bond in which electrons are unequally shared between atoms.

Nonpolar Covalent Bond

A covalent bond in which electrons are equally shared between atoms.

Hydrogen Bond

Weak attractions between molecules or between parts of a large molecule.

Isomers

Molecules with the same molecular formula but different structures, which can produce different properties and functions.

Solution

A mixture formed by a solute dissolved in a solvent.

Solvent

The substance in a solution that does the dissolving.

Solute

The substance in a solution that gets dissolved in the solvent.

Colloid

A mixture in which particles remain dispersed rather than readily settling out, such as protein in water.

Suspension

A mixture containing larger particles that can separate over time, such as blood.

pH Scale

A measurement scale reflecting hydrogen-ion ($H^+$) concentration.

Acid

A substance with a low pH ($1-6$) characterized by a higher concentration of hydrogen ions ($H^+$).

Base (Alkaline)

A substance with a high pH ($8-14$) characterized by a higher concentration of $OH^-$ relative to $H^+$.

Neutral pH

A pH value of $7$, representing a neutral concentration where acidic and basic properties are balanced.