Comprehensive Study Notes on Basic Chemistry and Biochemistry

Vocabulary practice flashcards covering basic chemistry concepts, subatomic particles, atomic bonding, chemical solutions, mixtures, and pH concepts from Chapter 2 Part 1.

Homeostasis

The body's ability to maintain internal stability.

Atom

The smallest unit of matter that retains the chemical properties of an element.

Proton

A positively charged subatomic particle located in the nucleus of an atom that determines the identity of the element.

Neutron

A neutral subatomic particle with no charge that resides with protons inside the nucleus of an atom.

Electron

A negatively charged subatomic particle that orbits around the nucleus and participates in chemical bonding.

Nucleus (Atomic)

The central region of an atom that holds positively charged protons and neutral neutrons together.

Atomic Number

The number associated with an element on the periodic table that indicates its total number of protons and electrons.

Isotopes

Atoms of the same element that maintain the same number of protons and electrons, but differ in their number of neutrons.

Radioisotopes

Unstable isotopes that emit high-energy radiation, which can be captured for medical imaging of organ function.

Thyroid Gland

A butterfly-shaped organ located anterior to the trachea that utilizes iodine to produce metabolic hormones.

Iodine-123

A radioactive iodine isotope given medically to assess thyroid gland function and metabolic hormone production through scintigraphy.

Valence Shell

The outermost electron shell of an atom where electrons involved in forming chemical bonds reside.

Valence Electrons

Electrons located in the outermost shell of an atom that interact with other atoms to form chemical bonds.

Octet Rule

The principle stating that an atom seeks to fill its outermost valence shell, typically requiring $8$ electrons for shells two and three to achieve chemical stability.

Electrically Neutral

The state of an atom having equal numbers of positively charged protons and negatively charged electrons, resulting in a net charge of zero.

Chemically Neutral

The state of an atom being non-reactive because its outermost valence shell is completely filled.

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.

Dissociation

The process in which an ionic compound (such as salt) splits apart into its individual constituent ions when placed in water.

Covalent Bond

A strong, stable chemical bond formed when two atoms share one or more pairs of valence electrons.

Isomers

Molecules that share the exact same chemical formula (such as $C_6H_{12}O_6$) but have their atoms arranged in different structural orientations.

Thalidomide

A drug previously prescribed to pregnant women for morning sickness that caused severe birth defects due to a single structural orientation switch in its molecular isomer.

Electronegativity

The measure of an atom's affinity or 'electron-loving' ability to pull shared electrons toward itself in a chemical bond.

Nonpolar Covalent Bond

A covalent bond formed when electrons are shared equally between atoms, resulting in no charge differences across the molecule.

Polar Covalent Bond

A covalent bond formed when electrons are shared unequally due to differences in electronegativity, creating partial positive and partial negative regions.

Hydrogen Bond

A weak attraction between a partially positive hydrogen atom in one polar molecule and a partially negative region on another molecule or region.

Solvent

The liquid component of a solution (such as water in the human body) into which solute particles dissolve.

Solute

A substance (such as sugar or salt) that is dissolved into a solvent to form a solution.

Solution

A mixture containing a solvent and very small dissolved solute particles that do not settle out over time.

Hydrophilic

Water-loving; describes polar substances that readily interact with or dissolve in water.

Hydrophobic

Water-fearing; describes nonpolar substances (such as fats or oils) that do not readily dissolve in or mix with water.

Mixture

A combination of two or more substances that are physically combined without breaking or altering their underlying chemical bonds.

Colloid

A mixture containing medium-sized particles that stay suspended in liquid without settling to the bottom.

Suspension

A mixture containing large particles that will naturally settle out to the bottom over time unless kept in motion.

pH

A measurement of the concentration of hydrogen ions ($H^+$) in a solution.

Acid

A substance that donates hydrogen ions ($H^+$) to a solution, yielding a pH value below $7$.

Base

A substance that accepts hydrogen ions ($H^+$) in a solution, yielding a pH value above $7$.

Buffer

A compound or chemical system that resists dramatic changes in pH by absorbing or releasing hydrogen ions.