General Chemistry and Chemical Concepts in Human Biology

Vocabulary flashcards covering chemical bonds, mixtures, subatomic structure, isotopes, and elemental composition of the human body based on lecture material.

Valence Shell

The outermost electron shell of an atom, where the number of electrons determines whether the atom is stable or reactive and governs its chemical properties.

Valence Electrons

Electrons located in the outermost electron shell of an atom whose interactions result in the formation of chemical bonds.

Molecule

Two or more atoms chemically bonded together, which may be of the same element (e.g., $N_2$, $O_2$, $H_2$) or different elements.

Compound

A molecule composed of two or more different atoms chemically bonded together, such as $H_2O$, $CH_4$, or $C_6H_{12}O_6$.

Chemical Bond

An energy relationship between atoms, rather than a physical structure, formed when two or more combined elements are chemically altered.

Suspension

A liquid mixture containing visible solid particles that tend to settle out if left standing, such as blood cells suspended in plasma.

Colloid

A mixture with two distinct components that appears opaque with particles that are not visible due to their small size and do not settle out, such as milk and cytosol.

Solution

A mixture of a solid, liquid, or gas in a liquid (usually water) where particles are extremely small, invisible, and do not settle out because one component dissolves in the other.

Solute

The substance that dissolves into the solvent within a solution.

Solvent

The substance (most importantly water in human biology) in which a solute dissolves to form a solution.

Solubility

The degree or ability of a solute to dissolve in a solvent.

Ion

An atom that has gained or lost electrons, giving it a net electrical charge because the number of protons no longer equals the number of electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons, resulting in a higher number of protons than electrons ($p > e^-$).

Anion

A negatively charged ion formed when an atom gains one or more electrons, resulting in fewer protons than electrons ($p < e^-$).

Mixture

A combination of two or more elements physically intermixed where the chemical nature of the atoms does not change, allowing them to retain original properties and be physically separated.

Mass Number

The sum of an atom's protons and neutrons, which account for virtually all of an atom's mass.

Isotopes

Atoms with the same number of protons but a different number of neutrons.

Radioisotopes

Unstable isotopes that undergo radioactive decay and emit radiation as they break down, used in medical imaging, cancer therapy, and biological research.

Mineral Elements of the Human Body

Seven elements—Potassium ($K$), Sulfur ($S$), Sodium ($Na$), Chlorine ($Cl$), Magnesium ($Mg$), Phosphorus ($P$), and Calcium ($Ca$)—that account for $4\text{\%}$ of human body mass.

Trace Elements of the Human Body

Thirteen elements—including Iron ($Fe$), Copper ($Cu$), Iodine ($I$), and Zinc ($Zn$)—that make up $1\frac{1}{2}\text{\%}$ of human body mass.

Element

A substance composed of only one type of atom that cannot be broken down into simpler substances by chemical means.

Electron Shells

Regions surrounding the nucleus where electrons are found; the $1\text{st}$ shell holds up to $2$ electrons, the $2\text{nd}$ shell holds up to $8$ electrons, and the $3\text{rd}$ shell holds up to $18$ electrons.

Major Elements of the Human Body

Four elements that make up $96\text{\%}$ of human body mass: Oxygen ($O$, $65\text{\%}$), Carbon ($C$, $18\text{\%}$), Hydrogen ($H$, $10\text{\%}$), and Nitrogen ($N$, $3\text{\%}$).