Chapter 2: The Chemical Basis of Life I: Atoms, Molecules, and Water (VOCABULARY)

Thirty vocabulary flashcards covering basic atomic structure, elements, bonds, and water properties based on the lecture notes.

Atom

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

Element

A substance that cannot be broken down into simpler substances by chemical means.

Nucleus

The center of an atom that contains protons and neutrons.

Proton

A positively charged subatomic particle located in the nucleus.

Neutron

An electrically neutral subatomic particle located in the nucleus.

Electron

A negatively charged subatomic particle surrounding the nucleus.

Atomic number

The number of protons in an atom's nucleus.

Atomic weight

The average mass of an element's atoms, accounting for isotopes.

Isotope

One of two or more forms of an element having different numbers of neutrons.

Periodic table

A chart organizing elements by increasing atomic number with data in each box.

Bulk elements

Elements found in the body in large amounts; the most abundant.

Trace elements

Elements present in very small amounts in the body (often <0.1%).

Big 4

The four most abundant elements in the body: oxygen, carbon, hydrogen, and nitrogen.

Oxygen

A major body element; part of water and organic molecules.

Carbon

A major body element; backbone of organic molecules.

Hydrogen

A major body element; part of water and organic molecules.

Nitrogen

A major body element; component of proteins and nucleic acids.

Valence electrons

Electrons in the outermost shell used to form bonds.

Valence shell

The outermost electron shell of an atom.

Octet rule

Atoms are most stable when their outer shell contains eight electrons.

Bond

A chemical force that holds atoms together in a molecule.

Covalent bond

A bond formed when atoms share electrons.

Polar covalent bond

A covalent bond where electrons are shared unequally, creating partial charges.

Nonpolar covalent bond

A covalent bond where electrons are shared equally.

Ionic bond

A bond formed by transfer of electrons, producing charged ions (cations and anions).

Electronegativity

An atom’s tendency to attract electrons in a bond.

Hydrogen bond

A weak attraction between a partially positive hydrogen and a highly electronegative atom in another molecule.

Water polarity

The distribution of charge within a water molecule due to polar covalent bonds, making it polar.

Cohesion

The attraction between water molecules driven by hydrogen bonds.

Adhesion

The attraction of water to other substances.