Lesson 1: Introduction to Biology, Chemistry Foundations, and Water

Vocabulary practice flashcards covering introductory biology, scientific method, atomic structure, chemical bonding, organic/inorganic compounds, and water properties.

Natural Science

The study of the physical and natural world using controlled experiments.

Scientific Law

A concise statement or mathematical formula that describes a pattern or regularity in nature, explaining WHAT happens.

Scientific Theory

An explanation of a natural phenomenon supported by many observations and experiments over time, explaining WHY it happens.

Peer Review

The process by which scientific information is checked by other experts for quality and accuracy before being published to the public.

Observation

The act of noticing and describing events or processes; the starting point of scientific inquiry.

Hypothesis

A testable explanation of a situation.

Control Group

The group in an experiment used for comparison that is not exposed to the factor being tested.

Experimental Group

The group in an experiment that is exposed to the factor being tested.

Independent Variable

The factor that the scientist deliberately changes in an experiment, which is plotted on the x-axis of a graph.

Dependent Variable

The factor measured or observed in response to changes in an experiment, which is plotted on the y-axis of a graph.

Quantitative Data

Data expressed as numbers obtained by counting or measuring (e.g., "The plant is $25\,\text{cm}$ tall").

Qualitative Data

Data consisting of descriptions using the senses (e.g., "The plant has green, oval-shaped leaves").

Homeostasis

The process by which an organism maintains stable internal conditions despite outside changes, such as plants adjusting stomata to regulate water loss.

Proton

A positively charged subatomic particle located in the nucleus of an atom that carries most of the atom's mass.

Neutron

A subatomic particle with neutral charge ($0$) located in the nucleus, having approximately the same mass as a proton.

Electron

A negatively charged subatomic particle that spins around the nucleus with a mass of approximately $\frac{1}{1800}$ of a proton.

Atomic Number

The number of protons in an atom, which determines the chemical identity of the element and equals the number of electrons in a neutral atom.

Atomic Mass

The total number of protons plus neutrons in an atom, which varies among different isotopes of the same element.

Isotopes

Atoms of the same element with the same number of protons but different numbers of neutrons, leading to different atomic masses.

Electron Shell Capacity

The distribution rule for electron energy levels: level 1 holds $2$ electrons, level 2 holds a max of $8$, and levels 3 and 4 are most stable with $8$.

Compound

A substance composed of elements joined in fixed ratios (e.g., $\text{H}_2\text{O}$ has $2$ hydrogen to $1$ oxygen; glucose is $\text{C}_6\text{H}_{12}\text{O}_6$).

Chemical Bond

The attractive force holding atoms together.

Octet Rule

The principle stating that atoms with fewer than $8$ outer electrons try to gain, lose, or share electrons to reach $8$.

Ionic Bond

A chemical bond formed by the transfer of electrons, where one atom donates and another gains electrons to form oppositely charged ions that attract.

Covalent Bond

A chemical bond formed when atoms share electron pairs, producing a molecule as the smallest unit.

Polar Covalent Bond

A covalent bond where electrons are shared unequally between atoms, generating slight charges on different regions of the molecule.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms, resulting in no charge difference across the molecule.

Hydrogen Bond

An attraction between a positive hydrogen atom in one polar molecule and a negative oxygen or nitrogen atom in another polar molecule.

Organic Compounds

Chemical compounds containing carbon and usually hydrogen, including carbohydrates, lipids, nucleic acids, and proteins.

Inorganic Compounds

Chemical compounds formed from elements other than carbon, such as water, acids, and bases.

Polarity

A molecular property where electrical charge is unevenly distributed across the structure.

Universal Solvent

A property of water referring to its ability to dissolve many substances because its polarity attracts other molecules.

Cohesion

The property of like molecules sticking together, such as water molecules binding to other water molecules.

Adhesion

The property of unlike molecules sticking together, such as water clinging to another substance.

Evaporative Cooling

The process where water absorbs large amounts of heat energy to break hydrogen bonds and transition to vapor, cooling the remaining liquid or surface.