Elements of Life and Macromolecules

Vocabulary flashcards covering elements of life, atoms, isotopes, and macromolecules.

Element

Substances that cannot be broken down further by chemical reactions, such as oxygen (O), carbon (C), hydrogen (H), nitrogen (N), calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), chlorine (CI), and magnesium (Mg).

Compound

Substances that can be broken down further by chemical reactions because they are made of two or more elements that are in a fixed ratio to each other.

Atom

The smallest unit of mass that retains an element's properties.

Protons

Subatomic particles with a positive charge.

Neutrons

Subatomic particles with a neutral or no electrical charge.

Electrons

Subatomic particles with a negative charge.

Atomic Number

The number of protons in the nucleus of an atom.

Atomic Mass Number

The sum of the protons and neutrons in the nucleus of an atom.

Isotopes

Two atoms of an element that have a different number of neutrons.

Radioactive Isotopes

Isotopes that decay spontaneously and release energy, used for processes including fossil dating and medical imaging (e.g., Carbon-14).

Electron Shell

An electron's potential energy, also called an energy level.

Tetra-valence

The unique ability of carbon to form four covalent bonds.

Octet Rule

Atoms will lose, gain, or share electrons to achieve an electron configuration of eight valence electrons.

Nitrogen Fixation

The conversion of atmospheric nitrogen into a usable form for other organisms by plants and some microorganisms, which is essential for the overall functioning of ecosystems.

Macromolecule

A large molecule that forms by polymerization, where monomer subunits form covalent bonds to make a polymer (e.g., carbohydrates, lipids, proteins, nucleic acids).