Module 1 Study Guide - Scientific Method, Chemistry, and Water

Vocabulary flashcards covering Module 1 study guide concepts including scientific methods, basic atomic structure, chemical bonds, and water.

Scientific theory

A well-tested explanation for a wide range of natural events that is backed up by a big body of evidence.

Empirical evidence

Information gathered through systematic observation.

Scientific knowledge creation

Knowledge created through empirical observation, experimentation, and the interactive testing of ideas using the scientific method.

Matter

Substance that takes up space and has mass.

Element

Substance that cannot be broken down further by chemical reaction.

Atom

Smallest unit of an element.

Four major elements of life

$C$, $O$, $H$, and $N$, which constitute $96.1\%$ of the mass of most living things.

Isotopes

Alternate mass forms of an element that have the same number of protons and electrons.

Electron arrangement

The structural layout of an atom's nucleus surrounded by orbitals, electron shells, and valence electrons.

Orbital

Specific regions where electrons move around a nucleus; each orbital can contain $2$ electrons.

Electron shell

A group of orbitals surrounding an atomic nucleus.

Valence electrons

Electrons found on the outermost shell of an atom.

Atomic stability

An atom is most stable when its valence electron shell is full, which can be achieved through chemical bonds.

Chemical reactions

Changes in the chemical composition of matter where cells constantly rearrange molecules by breaking existing chemical bonds and forming new ones.

Reactants

The starting materials in a chemical reaction.

Products

The end materials in a chemical reaction.

Covalent bond

A bond formed when electrons are shared between atoms, which can be polar or nonpolar.

Nonpolar covalent bond

A covalent bond where electrons are shared equally between atoms.

Ionic bond

A chemical bond formed when electrons are taken from one atom by another.

Hydrogen bond

An interaction that is individually very weak and not a true chemical bond, but gives water many of its essential properties.

Cellular water content

Cells are composed of $70\%$ to $95\%$ water.