General Biology I - Chapter 1 & Chapter 2.1 Vocabulary

Vocabulary practice flashcards covering introductory biology concepts, themes, elements, atomic structure, chemical bonds, and chemical reactions based on lecture slides.

Biology

The study of life, derived from the Greek words bio (meaning life) and logy (meaning study).

Cell

The smallest unit of organization that can be alive.

Element

The simplest form of a substance that cannot be broken down into other substances by chemical reactions.

Compound

A substance made of at least 2 different elements combined in a specific ratio.

Essential Elements

Elements required in large amounts by organisms to survive and reproduce; oxygen, carbon, hydrogen, and nitrogen make up 96% of living matter.

Trace Elements

Elements required by organisms in minute amounts (< 0.01%) to survive and reproduce, such as iron ($Fe$) and iodine ($I$).

Atom

The smallest unit of an element that holds all of the properties of that element.

Atomic Number

The number of protons contained in the nucleus of an atom.

Mass Number

The total number of protons plus neutrons in an atom.

Potential Energy (in Electrons)

The energy an electron possesses based on its location relative to the atomic nucleus; greater distance from the nucleus corresponds to higher potential energy.

Electron Shell

An energy level representing the distance of an electron from the nucleus of an atom.

Valence Shell

The outermost electron shell of an atom.

Valence Electrons

The electrons located in the outermost shell (valence shell) of an atom that can participate in chemical bonding.

Chemical Bond

An attraction between two atoms that holds them together, resulting from the sharing or transfer of valence electrons.

Electronegativity

A measure of how strongly an atom attracts electrons that are shared within a chemical bond.

Covalent Bond

A type of chemical bond formed between two atoms when their unpaired valence electrons are shared.

Molecule

Two or more atoms connected together by covalent bonds.

Nonpolar Covalent Bond

A covalent bond formed between two atoms with similar electronegativity, resulting in equal sharing of electrons.

Polar Covalent Bond

A covalent bond formed when one atom is more electronegative than the other, resulting in unequal electron sharing and partial electric charges ($\delta+$ or $\delta-$).

Ion

An atom that has gained or lost one or more electrons, giving it a full positive or negative electric charge.

Ionic Bond

A chemical bond formed when an electron is transferred from one atom to another, creating full opposite charges that attract each other.

Hydrogen Bond

A weak electrical attraction between a partial positive hydrogen atom ($\delta+$) and a partial negative atom (specifically $N$, $O$, or $F$).

Chemical Reaction

A process that leads to the change in composition of molecules due to the making and/or breaking of chemical bonds.

Reactants

The starting materials in a chemical reaction.

Products

The ending materials resulting from a chemical reaction.