atoms, ions, and molecules

isotopes

atoms of the same element with the same number of protons and electrons but differ in number of neutrons

octet rule

atoms obtain an outer shell with eight electrons and gain chemical stability through the loss, gain, or sharing of electrons.

covalent bond

formed between two atoms sharing the same electrons

ion

atom with an electric charge (positive or negative)

cations

ion with a positive charge

anions

ion with a negative charge

ionic bond

cations and anions binding together

molecule

composed of two or more different elements to form a different entity

molecular formula

numbers and types of atoms composing a molecule

isomer

molecules composed of the same number and types of elements but arranged differently

glucose + galactose molecular formula

C6H12O6

single covalent bond

sharing one pair of electrons between atoms

double covalent bond

sharing two pairs of electrons between two atoms

triple covalent bond

three pairs of electrons shared between atoms in some molecules

nonpolar covalent bond

two atoms that equally share electrons

polar covalent bond

sharing of electrons between two atoms of different types

amphipathic

molecules with both nonpolar and polar components

intermolecular attractions

molecules with weak attractions to other molecules

hydrophobic interaction

when nonpolar molecules are placed in water (or another polar substance)

intramolecular attraction

intermolecular attraction that occurs between different portions of a large molecule

organic molecules

molecules containing carbon (glucose, protein, triglycerides)

inorganic molecules

molecules without carbon (sodium chloride, hydrochloric acid, sodium hydroxide)

water (H2O)

polar molecule composed of one oxygen atom bonded to two hydrogen atoms

phases of water

solid, (ice) gas, (vapor water) liquid (water)

cohesion

attraction of water molecules

adhesion

attraction of water molecules and another substance other than water

surface tension

inward pulling of cohesive forces at the surface of water

solvent

liquid that dissolves one or more solutes

universal solvent

water

hydrophilic

water-loving (dissolves in water)

hydrophobic

water-fearing (doesn’t not dissolve in water)

acid

substance that dissociates in water to produce both H+ and an anion

base

substance that accepts a hydrogen ion

pH

value indicating the relative hydrogen ion concentration of a solution; any number between 0 and 14