Chemical Context of Life - Lecture 1 Chapter 2 Flashcards

Vocabulary flashcards covering fundamental chemistry terms, subatomic particles, atomic properties, chemical bonds, and reaction dynamics from Chapter 2 Lecture 1.

Matter

Anything that takes up space and has mass, including metals, oils, gases, living organisms, and rocks.

Element

A substance that cannot be broken down to other substances by chemical reactions, represented by a chemical symbol.

Compound

A substance consisting of two or more different elements combined in a fixed ratio, such as table salt ($NaCl$) or water ($H_2O$).

Emergent Property

A property where a compound possesses unique characteristics distinct from those of its constituent elements.

Essential Elements

Elements required for an organism to survive, grow, and reproduce. Four key elements (Carbon, Oxygen, Hydrogen, and Nitrogen) make up $96\%$ of living matter.

Trace Elements

Elements required by an organism in extremely minute amounts, such as Iron ($Fe$), Iodine ($I$), and Zinc ($Zn$).

Serpentine

A jade-like mineral containing elevated concentrations of chromium, nickel, and cobalt, in which specialized plant communities have evolved adaptations to survive.

Atom

The smallest unit of matter that retains the properties of an element.

Molecule

A structure consisting of two or more atoms held together by chemical bonds.

Protons

Positively charged subatomic particles located in the nucleus that determine an atom's identity.

Neutrons

Subatomic particles with no charge located in the atomic nucleus that determine an atom's isotope.

Electrons

Negatively charged subatomic particles orbiting the nucleus that form a cloud and determine an atom's chemical behavior and bonding ability.

Dalton

A unit of measure for the mass of atoms and subatomic particles, identical to the atomic mass unit (amu). Protons and neutrons each have a mass close to $1\text{ dalton}$.

Atomic Number

The number of protons in the nucleus of an atom, written as a subscript to the left of an element's symbol.

Mass Number

The total number of protons and neutrons in the nucleus of an atom, written as a superscript to the left of an element's symbol.

Atomic Mass

The total mass of an atom, concentrated almost entirely in its nucleus.

Isotopes

Different atomic forms of the same element that have the same number of protons but a different number of neutrons.

Radioactive Isotopes

Unstable isotopes whose nucleus decays spontaneously, giving off particles and energy.

Radiometric Dating

A method for determining the absolute age of rocks and fossils based on the half-life of radioactive isotopes.

Half-Life

The time required for $50\%$ of a parent radioactive isotope to decay.

Potential Energy

The energy that matter possesses because of its location or structure.

Electron Shell

An energy level of electrons at a characteristic average distance from the nucleus of an atom.

Valence Electrons

Electrons located in the outermost electron shell of an atom.

Valence Shell

The outermost electron shell of an atom.

Orbital

The three-dimensional space where an electron is found $90\%$ of the time.

Covalent Bond

A strong chemical bond in which two atoms share one or more pairs of valence electrons.

Single Bond

A covalent bond representing the sharing of one pair of valence electrons by two atoms.

Double Bond

A covalent bond representing the sharing of two pairs of valence electrons by two atoms.

Electronegativity

The attraction of a particular atom for the shared electrons of a covalent bond.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

Polar Covalent Bond

A covalent bond formed between atoms differing in electronegativity, leading to unequal electron sharing and partial charges.

Ionic Bond

A chemical bond resulting from the electrostatic attraction between oppositely charged ions.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Ionic Compounds (Salts)

Compounds formed by ionic bonds, such as sodium chloride ($NaCl$).

Hydrogen Bond

A weak noncovalent attraction between a hydrogen atom and an electronegative atom (usually oxygen or nitrogen in living cells).

Van der Waals Interactions

Weak interactions between molecules resulting from transient local partial charges.

Chemical Reaction

The making and breaking of chemical bonds, leading to changes in the composition of matter.

Chemical Equilibrium

The state in a chemical reaction where forward and reverse reactions occur at the same rate, causing reactant and product concentrations to stabilize at a constant ratio.