Atoms, Elements, and Basic Biological Processes

Vocabulary flashcards covering the basic chemistry of matter, atomic structure, subatomic particles, isotopes, principal human body elements, and essential characteristics/processes of life.

Chemistry

The science that studies the structure of matter.

Matter

Anything that takes up space and has mass.

Mass

The quantity of matter in an object.

Atoms

The smallest stable units of matter, composed of subatomic particles.

Protons ($p^+$)

Subatomic particles that have a positive electrical charge and are located in the nucleus.

Neutrons ($n$ or $n^0$)

Subatomic particles that are electrically neutral (uncharged) and are located in the nucleus.

Electrons ($e^-$)

Subatomic particles with a negative electrical charge that are much smaller than protons or neutrons (about $\frac{1}{1836}$ their mass) and whirl around the nucleus.

Nucleus

The center of an atom containing one or more protons and possibly neutrons, which mainly determines the mass of the atom.

Electron Cloud

The volume of space traced out by electrons whirling around the nucleus of an atom.

Respiration

A fundamental process of life involving energy production, in which oxygen ($O_2$) is obtained from the environment and carbon dioxide ($CO_2$) is released as waste.

Digestion

The mechanical and chemical process that converts the nutrients in ingested food into simpler substances that the body can use or absorb.

Circulation

The internal movement and distribution of oxygen, cellular wastes, and the products of digestion throughout the body.

Excretion

The process in which undigested food and the wastes of metabolism are eliminated from the body.

Cells

The smallest structural and functional units of organisms.

Responsiveness

The ability of living things to detect and respond to stimuli in their immediate environment.

Homeostasis

The stabilizing process by which living mechanisms maintain a relatively stable internal environment as external conditions fluctuate.

Growth

An increase in size that occurs as part of development.

Development

The natural progression in physical maturation of an organism.

Reproduction

The process by which organisms produce offspring, creating subsequent generations of the same kind of organisms.

Metabolism

All essential chemical processes that take place in living cells and organisms, including anabolic (building up) and catabolic (breaking down) processes.

Chemical Symbol

An abbreviation for an element recognized by scientists everywhere, often derived from English or Latin names.

Trace Elements

The $14$ elements present in the human body in very small amounts, such as silicon, fluorine, copper, manganese, zinc, selenium, cobalt, molybdenum, cadmium, chromium, tin, aluminum, boron, and vanadium.

Cofactor

A mineral or nonprotein compound that acts with proteins called enzymes to speed up chemical reactions in living things.

Radioisotopes

Isotopes with unstable nuclei that spontaneously break down and give off radiation in the form of moving subatomic particles or waves.

Radioactive Decay

The breakdown process in which the nucleus of an unstable isotope spontaneously breaks down and emits radiation.

Half-Life

The time required for half of a given amount of a radioisotope to decay.

Atomic Number

The number of protons in an atom.

Mass Number

The total number of both protons and neutrons in the nucleus of an atom.

Element

A pure substance consisting only of atoms with the same atomic number.

Electron Shell

A circular representation in a simple two-dimensional model where electrons occupy space around the nucleus.

Isotopes

Atoms of a single element whose nuclei contain the same number of protons but different numbers of neutrons.

Atomic Mass

The actual mass of an atom of a specific isotope.

Atomic Mass Unit (amu)

The unit used to express atomic mass (also called a dalton), where $1\text{ amu}$ is equal to $\frac{1}{12}$ the mass of a carbon-12 atom.

Deuterium

Hydrogen-2, an isotope of hydrogen containing one proton and one neutron, with a mass number of $2$.

Tritium

Hydrogen-3, an isotope of hydrogen containing one proton and two neutrons, with a mass number of $3$.

Atomic Weight

An average of the different atomic masses and proportions of an element's different isotopes.