BIOLOGY 2e Chapter 2: The Chemical Foundation of Life

Flashcards covering key vocabulary from the 'Chemical Foundation of Life' lecture, including definitions of matter, elements, atomic structure, isotopes, and related concepts.

Matter

Occupies space and has mass.

Elements

Unique forms of matter specified by chemical properties and physical properties that cannot be broken down into smaller substances.

Four Most Common Elements of Living Organisms

Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N).

Atom

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

Nucleus (of an atom)

The center of the atom that contains protons and neutrons.

Outermost region (of an atom)

The area that holds electrons in orbit around the nucleus.

Sub-atomic particles

Protons, neutrons, and electrons.

Proton

A sub-atomic particle with a +1 charge and a mass of 1 atomic mass unit (amu), located in the nucleus.

Neutron

A sub-atomic particle with a 0 charge and a mass of 1 amu, located in the nucleus.

Electron

A sub-atomic particle with a -1 charge and a mass of 0, located in orbitals.

Atomic Number

The number of protons in an atom, which is distinct for each element.

Atomic Mass

The mass of an atom, roughly equal to the number of protons and neutrons, expressed in atomic mass units (amu) or g/mol.

Isotopes

Forms of an element with different numbers of neutrons and thus different mass numbers.

Half-life

The time it takes for half of the original concentration of an isotope to decay back to its more stable form.

Radioisotopes

Isotopes that emit energy (subatomic particles) during decay.

Radiometric dating (Carbon dating)

A technique that takes advantage of the natural phenomenon of radioisotope decay to estimate the age of carbon-containing remains.

Periodic Table

A chart that shows the atomic mass and atomic number of each element.

Molecules

Two or more atoms chemically bonded together.