Chapter 2: Chemical Basis of Life

Vocabulary practice flashcards defining foundational concepts of general chemistry, subatomic structure, chemical bonds, chemical reactions, electrolytes, and blood pH dynamics.

Matter

Anything that takes up space and has mass; exists as solids, liquids, and gases.

Mass

The amount of matter present, commonly measured in grams.

Weight

The heaviness of an object due to gravitational pull on mass.

Atom

The smallest particle of an element that retains the properties of that element.

Element

A pure substance made of only one type of atom.

Compound

A substance made of atoms from two or more different elements chemically bonded together.

Trace Elements

Elements that the body requires in small amounts.

Proton ($p^+$)

A large subatomic particle that carries a single positive electrical charge.

Neutron ($n^0$)

A large subatomic particle that carries no electrical charge.

Electron ($e^-$)

A small subatomic particle that carries a single negative electrical charge.

Atomic Number

The number of protons in a single atom of a given element.

Mass Number

The total number of protons plus neutrons in one atom.

Isotopes

Atoms of the same element that have the same atomic number (number of protons) but a different atomic mass due to a varying number of neutrons.

Atoms interact based on electrons, not neutrons, so all

isotopes chemically react in the same manner

True

Molecule

A particle formed when two or more atoms are chemically bonded together.

Compounds

A substance made of atoms from two or

more different elements chemically bonded together.

Molecular Formulas

Formulas that depict the elements present and the exact number of each atom present in a molecule.

Bond

Connection between atoms in a molecule (involves electrons)

Electron Shells

Regions encircling the atomic nucleus that contain electrons.

Number of electrons in the outer shell determines

atom’s reactivity they want outer shell filled

True

Octet Rule

The principle stating that atoms prefer to have 8 electrons in their outer shell to gain stability.

non- reactive/ Inert

Describing atoms with filled outer electron shells that are non-reactive.

H and O have incomplete outer shells, so they will

lose, gain, or share electrons to have a stable

structure

True

Ion

An atom that gains or loses electrons to become stable and acquires a charge.

Cation

A positively charged ion formed when an atom loses electrons (such as $Na^+$).

Anion

A negatively charged ion formed when an atom gains electrons (such as $Cl^-$).

Ionic Bonds

Strong chemical bonds formed when ions of opposite charge attract.

Covalent Bonds

Strong chemical bonds formed between atoms that share electrons.

Two atoms of hydrogen (H) can combine to

form a hydrogen molecule (H2)

True

Polar Covalent Bonds

Covalent bonds in which electrons are shared unequally, producing a slightly negative end and a slightly positive end.

Non-polar Covalent Bonds

Covalent bonds in which electrons are shared equally between atoms.

Water is a polar molecule

True

Hydrogen Bonds

Relatively weak attractions between the slightly positive ($H$) end of one polar molecule and the slightly negative ($N$ or $O$) end of a nearby polar molecule.

Reactants

Chemicals that take part in a chemical reaction.

Product

The chemical result produced by a chemical reaction.

Synthesis Reaction

A chemical reaction in which a more complex chemical structure is formed from 2 or more reactants, requiring energy.

Decomposition Reaction

A chemical reaction in which chemical bonds are broken to form a simpler chemical structure, releasing energy.

Exchange Reaction

A chemical reaction in which chemical bonds are broken and new bonds are formed.

Reversible Reaction

A chemical reaction in which the products can change back into the reactants.

Catalysts

Substances (such as enzymes) that influence and change the rate of chemical reactions.

Electrolytes

Substances that release ions in water, enabling the solution to conduct an electric current.

Acids

Electrolytes that dissociate to release hydrogen ions ($H^+$) in water, increasing hydrogen ion concentration.

Bases

Substances that release ions capable of combining with hydrogen ions, decreasing hydrogen ion concentration.

Salts

Electrolytes formed by the chemical reaction between an acid and a base.

pH Scale

A system used to keep track of hydrogen ion concentration in a solution.

Acidemia

A state that occurs when blood pH drops to between 7.0 and 7.3.

Acidosis

A condition caused by low blood pH that makes a person feel disoriented and fatigued.

Alkalemia

A state that occurs when blood pH rises to between 7.5 and 7.8.

Alkalosis

A condition caused by elevated blood pH that makes a person feel dizzy and agitated.