Unit 1 VOCAB- The Chemical Context of Life

Vocabulary flashcards covering key terms from the lecture notes on the chemical context of life.

Matter

Anything that takes up space and has mass. Material of which things are made.

Atom

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

Subatomic Particle

The even smaller parts of an atom (protons, neutrons, electrons).

Proton

Electrically positive subatomic particle found in the nucleus of an atom.

Neutron

Electrically neutral subatomic particle found in the nucleus of an atom.

Electron

Electrically negative subatomic particle found in a cloud around the nucleus of an atom.

Element

Substance that cannot be broken down to other substances by chemical reactions.

Essential Elements

Elements known to be essential to life (CHNOPS + Ca).

Trace Elements

Elements required by an organism in only minute quantities.

Compound

Substance consisting of two or more elements combined in a fixed ratio.

Isotopes

Atoms that have the same number of protons but different numbers of neutrons.

Radioactive Isotope

An unstable isotope in which the nucleus decays spontaneously, giving off particles and energy.

Energy

The ability to do work.

Work

The ability to make something happen that wouldn't happen itself.

Potential Energy

Energy that matter stores because of its position or location.

Kinetic Energy

The energy of motion.

Activation Energy

The energy needed to start a chemical reaction.

Chemical Bonds

The attractions that hold atoms in interaction.

Covalent Bonds

The sharing of a pair of valence electrons by two atoms (H2, O2, H2O, CH4).

Molecule

Two or more atoms held together by covalent bonds.

Structural Formula

The abbreviation of a structure using lines to show bonds (H-H).

Molecular Formula

The abbreviation of a structure using subscripts (H₂).

Double Covalent Bond

The sharing of two pairs of valence electrons, such as in two oxygen atoms.

Electronegativity

The attraction of an atom for the electrons of a covalent bond.

Nonpolar Covalent Bond

Two atoms with equal electronegativity. The electrons are equally shared. Common example: Oil.

Polar Covalent Bond

Two atoms with unequal electronegativity. The electrons are found more on one side than the other. Common example: Water.

Hydrogen Bond

An interaction where a hydrogen atom covalently bonded to one electronegative atom is also attracted to an oxygen on another electronegative atom.

Van Der Waals Interactions

The brief interaction of positively and negatively charged regions of nonpolar molecules.

Ion

A charged atom.

Cation

Positive ion.

Anion

Negative ion.

Ionic Bond

The attraction of a cation and an anion that form an interaction. Strongest type of bond; results from electron transfer.

Ionic Compound

Compound formed by ionic bonds, also known as salts.

Chemical Reactions

The making and breaking of chemical bonds that lead to changes in the composition of matter.

Reactants

The starting materials in a chemical reaction.

Products

The final materials in a chemical reaction.

Dynamic Equilibrium

Reactions are still going on, but with no net effect on the concentrations of reactants and products.

Oxidation

Reaction in which one of the reactants loses electrons, becoming more positive.

Reduction

Reaction in which one of the reactants gains electrons, becoming more negative.