chapter 2

a positively or negatively charged atom

two or more atoms who share electrons

contains two or more different elements

is an electrically charged atom or group of atoms with an unpaired electron in its valence shell.

the forces that hold together the atoms of a molecule or compound

the force of attraction that holds together ions with opposite charges. one gives an electron the other accepts

positively charged ion

negatively charged ion

an ionic compound that breaks apart onto positive and negative ions in a solution

two or more atoms share electrons rather than gaining or losing them

forms when a hydrogen atom with a partial positive charge attracts the partial negative charge of neighboring electronegative atoms, most often larger oxygen or nitrogen atoms

occurs when new bonds form or old ones break between atoms

are chemical compounds that speed up chemical reactions by lowering the activation energy needed for a reaction to occur

when two or more atoms ions or molecules combine to form new and larger molecules.

A + B = AB

• split up large molecules into smaller atoms ions or molecules
• AB = A+B

they consist of both synthesis and decomposition reactions

AB + CD = AD + CB

the products can revert to the original reactants

AB = A+B = AB

usually lack carbon and are structurally simple

always have carbon, always have covalent bonds and usually contain hydrogen

dissolve easily in water = solutes that are charged or contain polar covalent bonds

molecules that contain mainly non polar covalent bonds are not very water soluble

a chemical reaction using decomposition and water to break down molecules into smaller molecules

when two smaller molecules join to form a larger molecule in dehydration synthesis reaction a water molecule is one of the products formed

can absorb or release a relatively large amount of heat with only a modest change in its own temperature

is a combination of elements or compounds that are physically blended together but not bound by chemical bonds

a substance called a solvent dissolves another substance called the solute

a substance that dissassociates into positively charged hydrogen ions H+

removes H+ from a solutions dissassocites into one or more hydroxide ions OH- and one or more cation

when dissolved in water dissociates into cations and anions neither of which is H+ or OH-

extends from 0-14 this scale is based on the concentration of H+ moles per litre. 7 = neutral lower then 7 is a acid and hire then 7 is a base

function to convert strong acids or bases into weak acids or bases

carbonic acid (H2CO3) can act as a weak acid and the bicarbonate ion HCO3- can act as a weak base. Hence this buffer system can compensate for either an excess or shortage of H+