A&P 1.2 Inorganic Chemistry

CHNOPS

Carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur

Atom

Smallest unit of an element retaining its properties

Proton

Positive particle in the nucleus

Neutron

Neutral particle in the nucleus

Electron

Negative particle outside the nucleus

Atomic number

Number of protons

Mass number

Protons + neutrons

Atomic weight

Weighted average mass of an element’s isotopes

Isotope

Same element, different number of neutrons

Valence electrons

Outer-shell electrons involved in bonding

Ion

Atom or molecule with a net electrical charge

Cation

Positively charged ion

Anion

Negatively charged ion

Electrolyte

Substance that forms ions in water and conducts electricity

Free radical

Reactive particle with an unpaired electron

Antioxidant

Substance that neutralizes free radicals

Molecule

Two or more atoms chemically bonded

Compound

Molecule containing two or more different elements

Isomer

Same molecular formula but different structure

Ionic bond

Electrons are transferred, forming oppositely charged ions

Covalent bond

Electrons are shared between atoms

Polar covalent bond

Electrons shared unequally

Nonpolar covalent bond

Electrons shared equally or nearly equally

Electronegativity

Ability of an atom to attract shared electrons

Hydrogen bond

Weak attraction between partial charges, often H and O

Van der Waals forces

Weak attractions from temporary electron fluctuations

Water structure

H–O–H bent and polar

Water polarity

Oxygen is slightly negative

Hydrophilic

Attracted to water and dissolves easily

Hydrophobic

Does not dissolve easily in water

Hydration sphere

Water molecules surrounding a dissolved ion or polar molecule

Cohesion

Attraction between water molecules

Adhesion

Attraction between water and other substances

Hydrolysis

Water is used to break a chemical bond

Dehydration synthesis

Water is removed to form a chemical bond

Thermal stability

Water resists temperature changes due to high heat capacity

Evaporative cooling

High-energy water molecules evaporate, removing heat

Solution

Very small particles remain suspended and can cross membranes

Colloid

Medium particles remain suspended and generally cannot cross membranes

Suspension

Large particles may settle or separate

pH

Measure related to H+ concentration

Acid

Releases H+ in an aqueous solution

Base

Accepts H+

Buffer

Resists changes in pH